All maps, whatever the mode or game, have a series of common design guides to follow so the player does not get frustrated or confused by the layout and structure when they play it. A map with good structure is one that guides the player along but still allows him to learn it quickly but still has depth to avoid repetition and boredom.
Only Have Whats Needed
Ask yourself why someone would want to go to each part of your map. If certain sections have no clear point to them then why bother having them at all? Players simply won’t go there and the sections will only serve to make the map more complicated and cluttered. Essentially only have the playable sections that are needed to advance the gameflow (note, this does not include sections that cannot be accessed but are there for decoration). For example, if you have two routes close to each other that lead to the same place, remove one of them or have it take a more dramatic route around.
You may want to add some neat idea you have had but it must still fit into the overall structure of the map. If you add an area just because it looks good or because it has some little gimmick then the map will suffer as a result. At the very least, compromise and add these features to the existing parts of the map rather than padding them on.
Simple vs Complex
Bad shape and structure in your map can often be because it is either too simple or too complex. If it’s the latter the difficult issue is to remove parts of the map you may have spent ages working on. To help determine which routes should be removed consider how often it is likely to be used and whether it leads to anywhere important or interesting. This is where having a good layout planned on paper beforehand can save you having wasted work.
There is nothing wrong with a map layout being complex or simple as such, but it ultimately comes down to how easily you can learn and work out your way around the map. Having a complex maps that is still easy to navigate is tricky to do, while overly simple maps suffer from a set of different problems.
Wherever possible you want to be able to at least make the player know he is heading in the right direction. For instance you could have the map on a slope (so he knows whether he should be going uphill or downhill), or have some large structure in the middle of map that can be seen from all around, such as a big statue
Both issues can be limited by planning out the layout beforehand. It won’t necessarily mean you will avoid having to radically alter your map up but if you work out the structure on paper beforehand you should be able to see the problem areas before you start building them. Ultimately you have to bear in mind that as you are the one making the map you will know immediately the best and quickest routes around. Other players won’t have that advantage so it’s useful to get a second opinion.
Knowing Where You Are
A key aspect of making sure players enjoy your map and do not get frustrated is to make sure they can easily work out their position. The first and most obvious way of achieving this is through the use of signs. However they should be simple and don’t rely on them to deal with a confusing layout. The other more appropriate and natural approach is to have landmarks that the players can orient themselves by. In very general terms this can be special rooms with supplies in or big structures that stand out from the rest of the map in some way.
Have A Main Route
Give the map a main route through it so that the players can use that as the key route to guide them around. Have minor routes coming off this which should directly or indirectly lead back to the main route (imagine it all as a transport network with the spine being like a motorway). If you are doing a deathmatch map then this main route should also follow the gameplay style you are using (linear, circular etc).
Keep Things Clear
Have clear entrances and exits. If you go into an area you want to be able to almost immediately see where you can go next even if it isn’t directly accessible. Don’t have doorways hidden away or dug into the walls out of sight. The same rules can also apply to maps that have specific goals to achieve. For instance, with Dustbowl for TFC, in each section you could see immediately what you had to do, whether it be to get to the exit or to get the flag to the goal at the other end of the map. One general technique often used to emphasize the exit/entrances is to use contrast. For instance the indoor areas can be quite dark and the outdoor areas where the routes lead to can be bright and sunny. Not only do you get contrast in the light levels but you can also get different color tones (dark colours indoor and light shades outside).