I know in matchmaking maps there are call outs for different parts of the map. However, how would I go about making call outs for my own maps. Is there any special tips one can give for call outs on custom maps?
Geometry wise you could place landmarks or color coated areas if that's what you mean. If you're thinking of names of areas, just keep it simple. Red Bridge, Blue Pad, Yellow Platform, Green Catwalk, etc.
I believe your referring to the call out system that is in Reach. Where the game tells what location you are in on the map next to the motion sensor. This system no longer exists in Halo 4. Not even for setting up in forge. Personally I don't really mind because a lot of those predetermined call outs in Reach were too long, and people invent their own call outs anyway. Call outs should be as short and too the point as possible, because your going to die if you start screaming, "I need help, I'm at Central Top Floor to the Right of Blue Spawn", for arguments sake. This is one of the main reasons we abbreviate call outs as well. For example, top-mid is top middle. The best way to invent call outs for one of your own maps is to take an overview screenshot and then add text boxes around the screenshot and point them to the position of your call outs. They have these for all the matchmaking maps in the Halo 4 Strategy Guide.
Honestly, the Halo 4 Strategy Guide doesn't even have great callouts. As Soulcrusher NP and Aurora have pointed out, simple is the way to go. Usually a color and the type of area it is. Areas on top of each other generally have the same first word and then a number. For instance, in Abandon, each floor of the central building is popularly known as Ring 1, Ring 2, Ring 3, with the area at the very top (not actual floor) being Ring 4. Obvious areas (like top mid, bottom mid) are generally good ideas to include - that is, if your map has a top mid or bottom mid. Hopefully that helped you a bit.
I saw a Pit remake that used dynamic lighting cleverly to create a red hued side (lit by sun) to represent red side and a blue hued side (shadowed by objects) to emulate the blue side. Using forge dynamics like that to your advantage in a subtle fashion can naturally create callouts that people will use without forcing them on players. It's how all good maps get their callouts.
I beg to differ, I think all the Haven call outs are good. Although some bigger maps like Exile, the call outs are too few. There are an abundance of area where there isn't a call out for. For the smaller maps like Haven, Solace, Adrift; for the most part the call outs from the Halo 4 Strategy Guide are pretty comprehensive and short enough. I had a bit of a chuckle when I saw what the Mohawk call out from Haven was.