The continents look good I think, A little too uniform in size but their shapes and placements are interesting and realistic. For the details, take your time, and sketch with an erasable pencil first, I'd say. The rivers look like they flow how they should, but you have lots of lines making up a single river when you really only need one line.
I concur with Lingon. I would also recommend creating a new layer over them, making the map transparent and tracing over the coasts a bit to give them a tad more detail. Right now they're a bit too straight, at least for my taste.
Also, I think adding islands to fill out the oceans a bit would be an awesome addition.
I can't wait to see how this develops!
Ah, thank you guys! I really appreciate the feedback :]
I'm going to look at more maps to get a better idea of how the coastlines should look--at the moment they are too straight, but I just wanted to have a general idea of what it'd look like. Now I can sketch over what I have and see what I get.
Islands are definitely a thing I plan on adding. Right now, I was only focusing on getting the main continents done. After that comes the islands, I think. As far as size goes, I'm not sure how big I'll keep things. I've just been working on 16k by 16k at 300 dpi--though I haven't thought much about scaling yet. I probably should.
Also, thank you for the feedback on the rivers--I was unsure of if they'd look realistic as is. I'll straighten them out and hopefully they'll look more believable.
If you need an example of coastlines, I'd offer my own map out of lack of knowing any others. It has its own problems, but I've been complimented on my coasts and islands, so it might help!
Oh yes, I remember that from last night. You're the dude that did the sexy islands.
Also, this is my first map too! -brofist- We can be noobs together