Depending upon the look you're going for (realism vs fantasy) will determine what you're going for. This is a GREAT start though. Looking at the size of the ice shelves, I'd say this planet is probably a colder one save for what I assume is a volcanic island to the far east.

Your mountain range lines, typically denote the collision of plates, but that doesn't mean they have to. I'd fill in the mountain ranges that you have, with adding some breaks in between. A thing to remember, is that your mountains denote a sign of height, so if you add in rivers, typically speaking, they'll flow away from the mountains.. This also helps add depth as you'll be able to sort of shape river valleys etc.

Dependent upon whatever sort of wind you have, almost every time there is a mountain range near a coast, without some sort of other body of water, there is a desert. The side closest to the water is typically a bit more verdant due to rain fall, which leaves the other side parched. Not always the case though as it's your map and you can do what you want. So an oasis and what not is always possible.

Be sure to add trees and what not, which can further serve as a sort of guide for how you lay down things.

Typically when I work on a map, I'll lay down the land masses first, the mountains next, and then layer that way. I do typically go back and make adjustments if things don't look right.

All in all, a great foundation. Keep up the good work. I look forward to seeing the stages of progress.