Uniforms changed during the war. Some factors which would influence uniform charcteristics would be location of the unit along with time period. For example a unit in the Army of Tennessee would not be issued from the same depot as a unit in the Army of Northern Va. Uniforms issued by different depots could be made from different material and would be put together in a slightly different pattern. Also supply considerations and pattern changes made during the war would also affect the look of the uniform. If the unit went to war with a locally provided 1st,uniform this uniform would wear out and the replacement depot issued uniform most likely did not resemble the previous one.
In short, pick a time period and location and start from there.