1. Think about what you're going to say to the official(s) before you approach them. If you're stuttering and searching for explanations, they'll get suspicious and ask you even more questions that you'll have an even harder time explaining. Also, they can be kind of intimidating at times, and this may make explaining things a bit more difficult if you're not well prepared.
2. Make sure your passport and whatever other documents that will facilitate your entry are ready when you approach the booth. This past June, the US started requiring a passport of everyone crossing the border, now required for ground in addition to air. Canada, however, does not have this requirement for ground travel, although a passport is probably preferred over any other form of picture ID.
If you're like me and have an unusual reason to enter and stay in the country, be sure to bring any other documents that will substantiate the legitimacy of your reasons. For example, since I'm still going through the immigration process, I bring all the correspondence I have received from the department of immigration to prove and show the status of my application. I've found that without this, the Canadian officers are more hesitant to let me in without a "fight," as I only have visitor status in the country and shouldn't be residing there as thus unless actively immigrating, which I am. I don't wait for them to ask me for this documentation; I just stick the most recent correspondence in my passport and hand them the whole thing. I also bring along a copy of our marriage certificate just in case the officers don't believe my claim of being married to a Canadian. I've never felt the need to show this nor have I ever been asked for it, but I have it in the event of an emergency.
3. Put your car in park. Officers will frequently go around it to look in your back seat and at your license plate, and if they desire to do so, they'll tell you to do this anyway for their own safety. Plus, you don't want to accidentally let off the brake and make them think you're making a run for it. A few officers may tell you to shut off the car altogether, although this has only happened to me a couple of times and is a matter of preference and not a rule.
4. Take off your sunglasses. I've never been able to get through without doing this, even when dealing with officers who now recognize me.
5. Think about what you're bringing in before you attempt to cross. It's not that you're not allowed to take any stuff you bought in one country into the other country, but there are rules limiting the transport of certain alcohol, tobacco, and agricultural products, as well as some high-value merchandise.
One day I was asked if I had any agricultural products on board. I peer down at the passenger seat and look at the banana that I had brought to eat along the way. I think, "oh crap" and say softly "Uh, a banana...?" I secretly prepare myself to throw it into the parking lot behind me in the direction of Canada. Luckily, before I hurl the forbidden fruit back into its country of origin, the officer says "A banana is OK." Whew! I had totally forgotten that you're not supposed to bring stuff like that over the border. While driving, I got to wondering: if a banana is OK, what isn't OK? A kiwi? A potato? 100 potatoes? A bonsai tree? Pig tongue? Well, according to the US Department of National Security website, all plant and animal products (including my banana) are supposed to be declared, inspected for "pests," and approved before going over the border. The guy apparently let me off easy.
Even though I've never had to pay duties on anything I've brought into either country, I've heard if this happening. In fact, Jeff was made to pay duties on a pack of cigarettes upon returning to Canada from the US. This is just dumb, but they have a right to do it, so beware.
6. Tell the truth. Even if you're entering the country for a reason that you may think will sound a bit shady, it's better to tell them the shady reason for entry than to look even shadier if and when they find out that you lied. You have to remember that your talking to the country's Department of National Security and not just a toll booth operator (not to discount the value of toll booth operators, but they're only going to deny you entry if you can't pay the toll or threaten their lives). Governments are taking issues of national security rather seriously these days, so you don't want to mess with it. I'm not sure what information they record when you talk to the officials (if any), but lying to a customs officer may bar your future attempt into the country as well.
7. Do what you're told. Unless it sounds unethical, do whatever the officials tell you to do without causing any trouble. There's been one instance when I was told by a Canadian official to park under the canopy where they tear apart vehicles and go inside so I could get my vehicle inspected. I have no idea why this particular officer (whom I'd never seen before) felt that I needed my car inspected as I told him the same stuff I've told the other officials everyday, but I did what I was told without question, even though it made absolutely no sense.
I go into the customs office and wait in like for 15 minutes, during which I witnessed a group of people get denied entry, which I think was a good reality check to remind me that this does happen and that I need to keep my shit together when crossing the border. I'm not sure why these "No Entries" (as the officials called them) weren't allowed in, but I wasn't about to ask in fear of becoming a "No Entry" as well.
Anyways, once I get up to the counter, I simply explain to the officer my usual speech, that I live in Abbotsford with my Canadian husband, am going through the immigration process and come through here every weekday as I work in Bellingham. The officer briefly glances at my passport and simply says, "OK, good-bye." and my car was never inspected. If this happens again, I'm probably not going to resist the officer by saying that this has already happened and the officer in the office didn't feel the need to inspect my car as I don't want it to appear as though I have something to hide. The officer in the booth recorded everything I said on a form and instructed me to give it to the official indoors, so maybe next time, if I resist the inspection, that officer WILL feel the need to inspect my car. I obviously have nothing to hide anyway, so I'll continue to humor them by complying to their insensible requests, even though they're a big waste of my time and completely unnecessary.
8. I'm not really sure how to list this as a "tip", but the first question I'm always asked is "Where do you live?" I not only give them the answer to this question, but I also go on to say, without stopping, that I live with my Canadian husband, am going through the immigration process, and work in Bellingham. For awhile I thought that you shouldn't say anything other than the questions you're asked in fear of saying something that will lead to an inspection or whatever, but I know they're going to ask this anyway, and it takes a lot longer for them to piece these facts together with a series of questions, so I just tell them so they get a quick, cohesive explanation. This isn't to say that you should jabber on forever, but I think it's better just to give them the essentials upfront and then let them go from there.
Upon beginning this entry 2 weeks ago on my Blackberry, I never thought I would have so much to say about this seemingly-simple experience of going through customs. Evidently, I do. Even though it's really annoying to have to do twice a day everyday, I think it's pretty unique. How many people spend everyday in two different countries? Sometime this year Jeff and I hope to move to White Rock, a beautiful town right on the Pacific. From there it will only be a half hour drive for me, and I'll be able to go through a border crossing with a Nexus lane (the crossing I take doesn't have one), making this process waaaaaaaaay easier as I can just drive right through without dealing with anyone. But until then, I will continue to cross according to the rules above and hope for the best.