To avoid unwanted resonance you typically do not want to put your monitor speakers directly on your desk. Most people use floor to ear height speaker stands. If you have to have your speakers on your desk a cost effective but not quiet perfect solution is to use Auralex MoPads. Ardán Audio has come up with a slick alternative. The elevation pro™ EVP-M1 stands tilt, rotate and in my opinion look really cool. Ardán is an Irish company based in Dublin and these stands are made in Italy.
If you have a small studio and have no space for standard speaker stands get a pair of these. Read here how speaker stands can improve your sound.