What can I do to speed these things up? I have two PowerColor 4GB Rx480 Red Dragons installed on an H97 ASRocks MB. Each is getting between 21 and 22 mh/s. I've tried changing the memory settings in WattMan to set "Memory" speed to 2020. I'm mining ETH using Claymore. Any tips? I've read these should be able to get 25-28 mh/s each.
Which kind of memory does thing cards have?
You should lower timings, there are plenty of guides about it.