I have a few ideas for future MOTF prompts. I'm not sure if some of them have been done (I haven't seen every MOTF contest) so, i apologize in advance if there's any repetition. Also, feel free to change the titles if you do accept any of these.
On the High Seas:
An alternate history map whose main focus is borders on the water. It could depict an alternate territorial waters dispute, the range of a group of pirates (like
this map of Somalian pirate attacks) or a map showing the range of a country's submarine attacks during a war. These are just examples, anything else focusing on maritime borders/areas of activity or control is acceptable.
A Mother and her Children:
Depict an alternate "colonial commonwealth" wherein a multiple countries and the country that previously ruled them maintain close ties (economic, diplomatic, military or any combination of those). This allows for organizations like the commonwealth, where a country maintains close ties to its former colonies or something like the Commonwealth of Independent States wherein countries that broke off from a land empire still maintain a connection to their former conqueror.
--- name pending ---:
A map depicting an alternate breakup of a Yugoslav/Pan Nationalist South Slavic state. It can be an alternate breakup of the OTL Yugoslavia or the breakup of an alternate South Slavic union (like an Illyrian federation led by Croatia or a Yugoslavia including Bulgaria or even one led by Bulgaria or whatever else you come up with). The only caveat is it must break up (mainly) due to internal pressures, not as a result of a partition by foreign powers (as was the case with Yugoslavia during WWII).
Back into the fold or Return of the Prodigal Son:
A map depicting a nation rejoining a multinational group (alliance, economic union, etc.) after being kicked out (using OTL analogues, it's like South Africa rejoining the commonwealth, Britain rejoining the EU or Yugoslavia or Albania rejoining the Soviet sphere of influence). The Alternate History aspect of it should obviously be visible in the map, maybe have visibly different borders, and alternate international union or something similar so that the AH aspect is visible without the writeup.
Layers and Layers:
Depict multiple levels of administrative divisions of a country
--- name pending ---:
Depicts human-made changes to the map (ie poldering, creating or draining lakes while making large hydroelectric dams, bomb craters? Whatever human-induced change to a landmass you can think of)