After crossing the boarder by land into and out of Cambodia I was able to experience a few things first hand that lead to a "I wish I knew that before" mentality. Due to that I kept notes as the whole experience progressed and after how long it took to get through from Cambodia into Thailand on a Sunday, it really made me want to fly instead of drive over. My number one hind above all else is even if you have an eVisa print off multiple copies of it as they will all want a paper copy.
Crossing: Bavet Checkpoint / Moc Bai
When it came from crossing into Cambodia from Vietnam it was fairly easy. If you are thinking about doing the land boarder make sure that you take a public bus (there are quite a few companies that do the route) as it is actually faster than if you take a private vehicle. On the public bus that crosses the boarder then they will collect everyone's passport and Vietnam visa. I had a eVisa for Vietnam and no where did it say I needed a copy to leave the country so without thinking I packed it but had a copy on my phone. They were not impressed about the copy on my phone but I was able to dig out the paper copy which made things go a lot easier at the boarder. If you have an eVisa for Cambodia they will also collect the visa copy and you pay them U$ 1 to process it. If you lose your eVisa then you will need to apply for a new one once you get to the Cambodia side.
Upon arriving at the boarder there will be a bunch of women that will want to take you dong and exchange them into Riel. Their prices are not bad and it is really difficult to find places that will exchange Dong's in Cambodia so take advantage of them. Also, there is a bathroom at the boarder that is free. There was one of these exchange woman that were standing outside of the bathroom and people kept giving her money as "payment" to use the bathroom although they did not need to and of course she didn't correct them.
There is also a small café before you head on in to a mosh pit while you wait for your name to be called so you can collect your passport. With your passport in hand, walk toward the officials to the left (opposite of where you came in) who will either check your passport or waive you through to the next official who wants to see your Vietnam visa and the exit stamp. They will then waive you out of the building.
Outside of the building there are a few souvenir vendors but nothing else as you are in no man's land as you head the short jaunt up the street to the Cambodian boarder. Here they have a few lines; those with eVisas, those without Visas, and those that are re-entering with a multi entry Visa. When we got there the building had no power so I'm not sure if this is normal but it is what happened when we were there. When it was my turn the guard took the copy of my eVisa out of my passport (do not staple it in even though it tells you, you can) compared me to my photo and then stamped it before sending me on my way into the country. Really easy and simple.
Crossing: Aranyaprathet / Poipet
When it came to leaving Cambodia and crossing into Thailand it was a little bit different. The building that you "checked out" of on the Cambodia side is no where near the boarder. It would be really easy to check out and then escape back into the country if you really wanted to. The whole area is very busy with lots of cars and people so you have to keep an eye on your items as pick pocketing is simple. The building is small with five lines that you stand in while waiting to get up to a guard that is behind glass. Once it is your turn they collect your eVisa and passport. If you don't have a second copy of your eVisa or you have lost it then you can pay a U$ 10 fine to leave. After your passport and visa have been checked they will then have you scan all of your fingers before giving you back your passport and pointing you out the door.
Once outside you will see a bar across the road, it has the only bathroom until you make it through the Thai boarder so I suggest you use it. If you don't need to use it then walk towards it and turn right down the road it is on and keep walking along this road, past the casino's (the house always wins), all the people trying to sell food / drinks (unless you want to risk food poisoning), and over the extremely pungent river while keeping an eye on your items. This is an area between two countries so if crime happens, I don't think either country would help you.
At the end of this 2 minute walk there is a building, this is the Thai boarder. Head inside until you find a "tourist information" kiosk where you will ask for a tourist card. There are a couple of desks and some pens to fill the card out. If you have a pen with you then I would suggest heading the stairs just to the left of the kiosk and filling it out in line (unless there is no line). Sunday's and Friday's are usually quite busy as people are trying to get to the other side to visit for the weekend / come home as well as just before / after regular working hours for the same reasons. We crossed on a Sunday and were in line for over an hour. There are no seats, bathrooms, drinks (except for a pot of water by the door that no one touched), nor food. It is air conditioned so at least there is that. As some people will be in a rush, they will try to budge so just keep your eye out unless you want to wait longer. The signs that say no phones are ignored by everyone and not enforced until you get to the front so feel free to youtube, facebook, ebook, and play games to keep yourself entertained just don't do it loudly or take photos as that will cause you issues. Also, on the other side of the wall are Cambodian nationals that need a work permit so although the line over there is shorter, it's not for you.
After waiting through the line to get to the front of the line someone may check to see that your tourist card is filled out properly before pointing you into a booth line. At the booth the person will check your against your passport, take your photo (without you knowing), and your visa (if needed, as a Canadian I didn't need one) before handing everything back to you. Then you headed out the back door, past a box with a photo of a dog on it, and down the stairs.
Welcome to Thailand. It smells even worse on this side.
