When making a map from scratch, my personal map-making philosophy is to try and make the natural elements of the world as realistic as possible, because natural stuff is more believable. This doesn’t mean you can’t add fantasy geography in (islands floating in the air, magic forests, etc.) but things like topography, climate, and vegetation should be rooted in reality. Even if it’s a reality with different rules than our own.
Instead of giving you the steps to creating a world, I’ll outline some basic world-building rules and then describe a few ways to achieve a world that follows those rules. Ready? Let’s go!
Mountains usually appear in ranges. They don’t just clump up. Mountain ranges and huge canyons are usually the result of a complicated geologic process where tectonic plates push or pull against each other. Keeping this in mind will also let you create some realistic looking island chains.
This is a great resource for drawing a basic height map using tectonic plates: http://www.emmalindhagen.com/2015/11/worldbuilding-wednesdays-step-by-step-for-tectonic-plates/
You can design your coastlines within your tectonic plates however you want, really, just use the tectonics as a guide.
Wind is important to determining your moisture which is important to determining your rivers, lakes, and biomes. In real life, wind is pretty complicated and runs in ribbons around the world from high to low pressure areas. Determine this on your world map, or if you’re doing a local map just decide on a local prevailing wind.
Moisture is a little harder to deal with. But the basic rule you can follow to keep things simple is: Wind picks up water over the ocean and deposits it on land in the form of precipitation. More moisture is deposited the higher the elevation is because as air rises, it becomes less dense and can carry less water, so it drops more of it. This means mountainous areas get more rain. I’d make a new layer and determine roughly where the rain is going to fall. This is a really important step!
So as wind blows over mountains, it loses its moisture so there isn’t any moisture on the other side (or much less). This means one side of a mountain will have lush forests and the other will have dry grasslands or even a desert.
Rivers okay now you have a moisture map. Pick where the most moisture is and draw rivers from those areas to the coastline. River rules to follow: 1. Rivers always flow downhill. 2. Rivers do not split, they always merge. 3. Rivers meander, so be creative with giving them a snakelike shape 
Recalculate your moisture map and include rivers as a source of moisture. The land around rivers should have its moisture value increased.
Temperature this one is generally easy. It’s cold north/south, then gets warmer around the equator. Also, elevation = colder. So mountains are going to be colder than grasslands.
Biomes Pick where to put your biomes using temperature and moisture. Here’s the table most people use:
City placement! Now you finally get to place your cities. Cities grow from towns, and people need fresh water, food, and trade. What supplies these things? Rivers! So pick places along rivers in moderate climates (or whatever climates you choose for your fantasy race to be most at home in) and plunk down a city. Prioritize confluences (where rivers join together) and estuaries (where rivers meet the ocean).
Making regions Draw up regions between cities to create countries or principalities, etc. Use geographic features like rivers or mountain ranges or forest lines to make realistic looking borders. Borders can also be influenced politically so be creative
Naming your stuff I had a lot of files on my old Realms project to tackle naming. My naming was mostly for germanic place names because they’re so modular and easy to snap together. Place names aren’t random: They are heavily influenced by the geography or nature around them. Near a forest? -wald, -forst, etc. are good suffixes. In English fantasy: -forest, -wood, etc.
Near a river? Name it after the river. That’s where we get Prackenbach, Donaustauf, Regensburg, etc.
At a loss for what to call it? Mix in some colors and slap a generic suffix on like -ton, -town, -ville, etc.
https://trello.com/c/wCHOdWMD/162-implement-a-new-naming-system This might help you along. I did a huge amount of research creating a logical procedural naming system for my Realms project last year and I think it can be used to make realistic and cool place names.
That’s about it when it comes to my advice for worldbuilding but remember: The story comes first! You’re welcome to use my generator (or my old one too, it’s got more features but is less polished).
