That looks good, though many shapes are a bit too recognizable. I suggest stitching together smaller segments and mixing them with more of your own coasts. Overall, it looks really nice, but looking closer, it's easy to find Italy, Greece, Argentina and Chile, most of North America, etc.

As for the geographical features, thinking of the tectonic plates will give you likely mountain locations, which in turn will show where rivers would be (there's a great tutorial in the tutorial section talking more about this), and rivers give water to forests, and what remains after that becomes desert. Simplified, but it's a starting point perhaps?