My Miss Fortune build is intended to be a lane dominant support that primarily pokes down the lane opponents with e and q, and ends up doing AoE teamfight damage in the late game (especially in dragon or baron fights). I decided to try this idea out because I like MF as a character, and I had some success (although sample size is still relatively small). Ultimately, she has an ADC focused kit that uniquely lends itself to be used in support, and when Umbral Glaive was released I remembered seeing this once or twice in the past, and I wanted to try it.

I chose electrocute for lane pressure, as it can be activated by e+q+auto, as well as the domination tree being good for MF in general. Cheap shot because you slow with e at the beginning of any extended fight, zombie ward because you will be killing a lot of wards with Umbral Glaive, and ultimate hunter because you will want your ulti as often as possible. Inspiration is a good secondary for almost every support, since you get the max CDR increase as well as item CDR, and future market is free money. Take stopwatch instead if you're planning on building Zhonya's.

This is an AP build, so Spellthief's is the support item, Umbral Glaive is huge in vision denial, MF uses spells and autos both, so Lich Bane makes sense, and since you have Umbral Glaive and finished support item, Farsight Alteration is the optimal trinket. Your boots should be Lucidity unless you are already fed, in which case go Sorc Shoes and rush AP items (potentially straight into carry items instead of Umbral Glaive). If the opposing team has assassins or heavy burst, consider getting a Zhonya's, but if they mostly do DPS or can be blocked by the frontline, take Luden's instead. Only get Rabadon's if at that point you are the most fed member of your team.

I am still exploring this build, so this may not be totally optimal, and if you have an idea to improve it, I would love to hear it. I'm also a silver player, so this might have varying levels of success at different ranks. Keep in mind that League of Legends is supposed to be fun, so change it up a little sometimes. Don't get hooked by Blitzcrank.