Hello!

As the title says, I'm looking for advice on where my rivers should begin. I'm familiar with the age-old mantra "Rivers never split", but what about "Where do they begin"?

Now, I know most rivers begin in the hills and mountains of the world. However, with the exception of springs, where else can they originate? I have a first-time map that I'm building up, and my rivers look strange just coming out of the mountains all the time. On the other hand, I think they might look even more strange just popping up in the middle of grasslands. I suppose some could originate out of certain lakes, perhaps?

I want to see what my options are. Any advice you could all bring to the table would be most appreciated.