Cryptomixer.io in my experience because only for 0.001BTC i can mixed coins and it went fine, i don't know about other services never try them before, i can recomended it for 0.001BTC more than it, take the risk by your self. 
Well, cryptomixer offers the possibility of mixing coin amounts as low as 0.001BTC, but that doesn't really make any sense IMO.Mainly because of the fact that from every amount that you are sending to cryptomixer, 0.0005BTC will be deducted from it, plus the chosen fee of course.
That's why Bitmixer is not allowing amounts below 0.01BTC to be mixed since it's not worth the time and hassle.