Here's my basic process;
- I start with a ton of research (might not be important to you or fit your project).
- Make a basic plan in Photoshop (paper works too) that resembles an overhead map like you would see in RO.
- Make some rough terrain and basic block buildings in order to get the overall scale of the map right. Play test this to make sure you've got it right.
- Spend a few hours going through the static mesh packages and placing any mesh I might use in the map into a giant junk pile. I find that making a junk pile is faster than searching for statics all the time in the packages and it also keeps my overall unique mesh usage down, which is important for optimization.
- At this point I do some more work on the map, sculpting the terrain and fleshing out the buildings.
- Once I have a basic map going I'll add in the Objectives and PlayerStarts and do some play tests.
- Sometimes I'll take a break here and start working on custom static meshes and textures but usually I create them as I need them.
- After that it's just more work adding statics, textures, etc. with a few play tests in between to make sure I've still got a fun and functional map in the works.
- Finishing touches include bot paths, and overhead map, and a whole lot of testing.
- The last step is packaging up everything into a nice tidy bundle and getting it on the net so players and server admins can access the map and hopefully enjoy it.
Be prepared to go back and make fixes because no map is ever released perfect the first time. It's best to name the first release RO-WhateverYourMapNameIs_Beta1 so people know it's a beta and to keep the full name saved for the final version.
Your process will probably be different but hopefully this will give you an idea of the basic work flow. Hope you have fun and be sure to ask questions along the way!