i) Have a list of map makers who want to contribute
ii) Ask each of them to nominate one or two of their favourite maps, possibly compromise to get a range of maps from 1v1 to 5v5
iii) Produce a beta download, with a thread with screenshots of the maps
iv) Ask for the maps to be tested online, and for reports and replays, over a couple of months
v) Maps with 'votes' in the form of positive reports and replays posted are then included in the final.
vi) A final pack, with credits for both mapmakers and beta download testers with posted replays.