The First thing is something I dubbed Creep webbing/Creep Threading.
It can be done with neutral tumors on the map as well as without them (just a zerg player would have to start spreading creep to make it visible obviously). Having creep already on the map also means that zerg would not have to actually have to send overlord or creep tumors all the way to that point to gain boosts. Effectively making these spots higher value terrain to be battled over. A player could even possibly use a strategy to send queen out to drop tumor(s) at this island of creep somewhere on the map. I believe a player can also use detection and kill the neutral tumors in the likewise.
Basically what you do is place lines of unbuildable pathing and creep blockers in the same spaces. You can actually draw out all kinds of designs in this, but the least confusing most effective way of doing this is just to do 1 line of block with a space on one or both sides to let one square in to the next pathable line.
This effectively makes it so zerg creep: Spreads faster, Needs less tumors, move across map more quickly, have less creep occupying in same space. So it still keeps their speed buffs but lose the ability to build anywhere.
Zerg units don't actually have to be 100% on the creep to net the speed benefits, they can be on the fringe edges of it before they lose the the boost. Which is exactly how this works.
[spoiler=Pics of Webbing]
closeup of hidden webbing in map editor.
closeup of revealed webbing in map editor
Larger view showing building pathing blocking in yellow
trying out designs
closeup of revealed webbing but unexplored
Same area but explored
More similar areas (slightly different designs).
Overlord diarrhea or crop circles????
The second concept is not all that game changing but is interesting and can be fun at the least. I don't really have a name for this but I guess I'll just call it Fakey Ramp for the sake of simplicity.
So obviously this would be best implemented into a main base, but could also be used (and arguably has been used on other maps) on other places around the map.
What it is, is a normal narrow choke to a main on level ground probably 3 spaces wide to simulate a normal ramp width ( I had to use doodad rocks and cliff to make it just right) and on this narrow choke you will place LoS blockers. The thickness of these is totally up to you but I think 1 or 2 rows juxtapose emulates a ramp best.
So since high ground in this game does not cause miss rate, but instead has the advantage of being able to see them and shoot them while they cannot see or fire back it essentially just makes acts like a ramp where neither player can see in or out. This is arguably terrible for the defender (unless they are zerg or terran where they can have air units very early to see over the shrubs).
So to balance this out, I threw a XWT inside the main base. The placement again, is up to the creator but I think a placement where it doesn't show too far outside on the main path as well as doesn't show too much around the outskirts around the main base (for air detection) would be optimal.
The cool side effect of this is that the XWT can be placed in such a distance that a scouter of an unknown base could just tap the tower to see if the player is there rather than going all the way into empty bases (saving a bit of scouting time).
Also, the owner of the XWT in their main would have to choose when to devote units to sitting at the tower to see outside their own base, so there is a little dynamic of if/when you should use workers to see instead of mine/build.
As a side effect to this I noticed that larva/eggs will set off XWT indefinitely. So zergs could place hatch next to it to keep the tower on all the time (until an enemy shares the tower with their unit).
Another technique using this concept would be to send some (or drop) units onto the tower the moment you are going to attack the front of the base completely switching the advantage of the choke around to you since you have units on both sides and can see both inside and out while they can't (its like flipping a ramp around like a light switch) Maybe we can call it lightswitching?
[spoiler=Pics of Fakey Ramp]
Showing XWT range
Here I put a bunch of unbuildable pathing to make it so tumor would have to be spread from only the very edge of the LoS shrubs to reach the green squares for the next tumor.
Showing creep spread unexplored
Showing tumor distance
The third concept I used was the implementation of half gold bases. Where I just alternated the minerals to gold/blue within the same 8 patch base. So it's only going to mine out half as fast as a gold but still can give some explosive mineral bonus like a gold base can.
edit- blah spoiler breaks the image layout