When you enter a foreign country, you will have to go through Passport/Immigration and Customs. Here you will have your passport stamped to gain entry to the country. You will also have to go through customs and possibly have your luggage inspected.
This will depend on what you declare on your arrival form. This is the one that you fill out in the airplane. It will also depend on how you look.
You may think that I am talking about profiling whether it be racial profiling or otherwise, but what I am talking about is how you appear to the security inspectors.
I always dress half-way decent when I travel. I do not wear a suit and tie but at the same time I dont wear cut-off shorts, sandals and a ripped shirt. I dress in-between.
I usually wear a pair of jeans, collar shirt, and loafers. Loafers make it a little easier to get through security at the departing airport and the jeans and polo type shirt are comfortable. I recommend you wear comfortable and presentable clothes.
If you look like a shabby bum the chances are higher that you will be inspected.
It is also recommended that you dont wear anything that will bring attention to...