OOC: @norwegianbikeman, are you working ONLY in .jpg format when you make these maps? When I see all the artifacts left over from edits, I would guess that is what you are doing. If that is the case, then... WOW!!! You are doing a lot of work on editing these maps!
Since I have not worked with GIMP, I can't explain how to use the native format for GIMP, but I do know that GIMP does support layers. It will save you a ton of time if you made all changes in the native format by moving the individual (layers) components instead of editing them. Simply grab and move a player or enemy marker and that job is done. Keep moving markers until all are updated to the new positions and then save the work in its native format so that the next day you can move everything again. For posting, you "save as" a .jpg file which flattens all layers into one and that's the image you use in the post (but you still have the original image with the layers). The next day, you simply open the original file with the layers and move stuff around again.
If you don't know how to use layers in GIMP, I believe it would be well worth the time to watch a few tutorials about how it is done, especially if you intend to do these games for a long time. At first it will seem like more work, but after you get used to it, you will understand how much time it saves.
I'm pretty confident that GIMP can do everything Photo Pos Pro can do, so if you wanted a fatter building than the one I gave you, you could simply select it and pull on one side to make it fatter. You can also turn it in any direction to get whatever angle you want. If you want the same proportions but bigger, you grab a corner and drag it out to the size you want. Or, conversely, drag the corner in to shrink its size. If you don't like where the building is, grab it's center point and drag it to where you want it. If you want to turn the building on an angle, grab it's handle and move the mouse to the angle you want. Once you are happy with it and want an exact copy, click on "copy" then "paste into current image" and you have an exact copy at the exact same angle and size. Click it's center and drag it to a location on the map. Now you can manipulate the copy any way you want (turn, resize, etc.).
I love your game and want to help you run it in the most efficient way possible. If GIMP is too complicated, you may wish to download Photo Pos Pro and use that. They have quite a lot of tutorials right within the software (at least the old version does). I like the features in the old version, so am reluctant to update in case the new one doesn't include them.
Here is a screen capture of what I'm talking about:
a been using gimp for years and Photoshop to. a have a system its fast. a tried before whit layers etc but figure out its faster how a do it now. a use layers when its fog etc. now it take me just a few min to update a map.
Oh wow! Care to share how you can update in minutes, because it takes me about 15 minutes to do a simple update on my maps; longer if it is more complex. Mind you, I'm slow at everything. I'm always willing to learn something new though.
am using the clone tools in gimp super easy to move around objectives. a dont know how your program has it.
Ahhhh... You clone the piece you want to move to a new location, then erase the old location? That's pretty clever. However it is still one extra step having to erase the old location. Drag to move is just 1 step and without the worry of having a correctly-sized clone brush.