When purchasing long sleeve tees, you'll need to think about three things 1) the design or saying that is on your tee that will make you unique 2) the material that the shirt is made out of and 3) the length of the long sleeve tees that you will wear.
Consider whether or not the long sleeve tees are appropriate for the weather. For example if you are going to the beach to lay in the sun then you would want to wear a short sleeve shirt. It is more appropriate to wear your long sleeve tees in the fall and winter when you want to keep warm. Make sure that your long sleeve tees are made out of the most high quality material available such as 50/50m or 100% cotton, this will ensure that your shirt last for a long time and does not shrink. Another important thing to consider is the graphic that is on the long sleeve tee, for example if you are going to a bar then you may want to wear bright yellow so that you stand out like a sore thumb, maybe this will help you get some free drinks. You should make sure that the bar allows you to wear the graphic on the long sleeve tees that you plan on wearing so that you don't get thrown out by the bouncers for wearing something inappropriate. if you are wearing blue jeans then the graphic on your long sleeve tees should have a complementary color in it. Last but not least your graphic tees should help make you stand out. You want to wear something that is unique, because there is nothing more embarrassing than going to a party and seeing someone wearing the same graphic tees as yourself. A good place to find a long sleeve tees is on the web is at a web site called urbanmist.com.