Fabfilter makes some amazing effects and tools for production. Right now they have 40% off their bundles until April 24th 2014 it looks like. That's a great discount especially considering the quality of the effects. Looks like it also extends to just individual effects too.
Saw this article about using a controller like launchpad to generate some effects to add some variety to your tracks. Definitely worth a read and there's a video where he demonstrates the technique as well. Check it out.
For those of you that are into doing your own basic mastering or want to learn some additional info about mastering in general there's a new vid by ArtFX on youtube where he goes through and masters a track.