I like to use the army digital pants for sure, cheap surplus, also most come with padded knees for those days you have to beg to get out of the house and play.
I also use one of the sniper scarves, buddy gave me one when he came back from Iraq, will keep your neck actually pretty warm and covers the gun up if you need to. made of a mesh so you can toss it over the scope and see through it, its pretty cool. as a side note, ive had to use it as a make shift rope while trying to climb out of a muddy part of the badlands after getting caught in the rain, lol was slick as snot, took us a very long time to get out LOL.
I like to mix mine up, for the most part, that way I dont look like one giant blob, rather a couple little ones LOL.
up here I find that some of the duck/reed patterns work well as there is alot of crp and sloughs.
winter I have a mix of nat gear and some cabelas pattern.
basically I go to the bargain areas, look for something I think will work for cheap, then let my buddys tell me if it seems to blend, its about all ya can do.
Good luck.