Mazing TD level design

I’ve hit a wall with my TD game project, I need a lot of levels to make a campaign, but I want them to look pretty and be playable and enjoyable. Given this is a mazing TD, I have a set of checkpoints for monsters to visit before they will count for loss of life, but also I need some visual impression that a level is located somewhere in terrain, be it forest or mountainous range. These can’t be generated dynamically with my skills (well, given that my forest was the slowest of all and absolutely unacceptable to generate background…) so I need to have them preset. The level should have: monster pass matrix (two levels), “busy” places matrix (determines if I can place towers there or not), and at least one level of art structures (background, detailed to some extent).
The question is: What I should start with, art or concept, or evolve both until it’ll be a correct representation of a level?

this is a mazing TD

You’re only just beginning your project and already thinking this highly of it? sheesh!

I kid… I’m having trouble following everything you put out there but I’m going out on a limb here and just assuming you’re building a top-down grid of changeable tiles? If so, I’d just do plain colored squares for now. That’d be easy to do dynamically… or you can just draw out the squares in paint or wherever you choose to do your graphics and perhaps add small, crappy 1-minute touch-ups to them (crappy, and I stress crappy, little trees or rocks) here and there as you go just to get a feel of the direction. If you just save over the file you’re importing, changes on the fly should be no prob.

Next optional step might be to decide whether or not to give the tiles their possible edge combinations.. like where forest touches road or water.

^just a quick google image search for reference

I’d just make them solid colors for now (bucket fill green for forest, brown for road…) and worry about the pretty graphics later. You never know when you’ll want to change it up and possibly resize your game tiles. It’d be much easier if you had most of the code and gameplay fleshed out before-hand.

Just use your shitty programmer squares until you’re pretty sure you’re ready to make a commitment to graphics.

My apologies if this wasn’t what you were asking.

well, the engine of the battle is already up and running :D I need more levels, since the level I used was taken straight from GemTD. I am able to even populate the levels with various monsters if I’d find me some good sprites without big hassle. I need the proper background and grid(s), and I can’t understand should I first draw some art (will likely consist of heavy clipping off nature photos and slapping em over a single JPG) and then draw a passability grid based on the image, and THEN place my checkpoints and extra layout should I need any, or first draw a grid and then align the image to fit it.

Well, I was asking for a little higher quality output. While tiles can do for a while, as well as testing, I expect the result to be kind of monolithic and predesigned (like what’s in Gemcraft Labyrinth, about what GiaB has as background for his levels).