I don't normally have a big issue with compliments, but there are a few cases that still don't come naturally to me apparently.
1. for time compliments with regular objects, you must place the time compliment before the object:
学了两年中文. Your teachers and some grammar books will tell you you can add a 的 between the time and object, at least in this case, and you can, and people might say that or write that, but the test will most certainly not be like that.
for time compliments with 人名 or for those who like r, 人名儿， the time compliment can in theory go before or after the object, but just forget that. For all intensive purposes it has to go after the object.
2. if the object of a verb is a place and the compliment is a direction, the compliment must be placed after the place.
请进教室来。 and NOT 请进去那个教室。
Ok, more comments and compliments about compliments later will likely involve stranger and more obscure cases