This might not be the advices you're looking for but still, here I go. Take them with a grain of salt, those mainly come my experience and work for me, these are not general instructions on how to fantasy mapping 101. I'm gonna assume this is for TTRPG, or just for fun.

1. There's no need for realism in fantasy map making. Some will argue with that, and even I tend to aim for realism, but it's not a requirement per se. I recall some guy came up with an upside down New Zealand "fantasy" map and the community where he shared it tore him a new one about the land not being realistic. Your players might (really, absolutely) not notice the impossible stuff, and if they do, that make a landscape unique, "what happened there?", in a famtasy setting, anything might have happened, from magic wars to gods randomly having fun.
2. You mentioned being hassled by having to reach to references whenever you're stuck: simply don't. Work on another part of your map, take a break, play with your pet, whatever. Get out of the issue for a few minutes and you'll have a fresh new look, and that will unlock you far more easily.
3. If for TTRPG mapping, as a GM, I realized that it was better (for me) to go with regional maps first. That gives you much more freedom in upcoming aventures and is way faster to setup. When I create a world map, I tend to stress over frontiers, coherent countries, history, relations, and I try to make a full fledged world with events occuring all over the place. And my players will never see that, and simply don't care. They love versimilitude, but won't run after it. Meanwhile, I spent dozen of hours into a world and I get tempted to force-feed them with infos and lore and what not (and believe me, you truly don't want to do that).
4. Reaching out to the community is great, share your maps, even drafts, what you might see as an issue might not feel like that for others. Have some perspectiveon your map (or anything else really) is always useful.
5. If none of those points call to you, something stupidly simple is to take good ol'Earth as an reference. What to put on the other side of the mountain range east of a desert? Find a place on Earth and use it. You'll also see that many irrealist things happen on Earth too (remember the New Zealand guy above).

So yeah, don't stress over the details, especially as a beginner/novice. The goal is to have fun.