Generally, I find the OLL “dot” cases frustrating — there are a bunch of them, they’re hard to identify/distinguish quickly, and their algorithms are long. A few months ago, I worked on a couple OLL dot cases that I had previously twolooked. Those came rather easily. Then I got sidetracked by the Megaminx, 4×4 modding, and PLL time attacks.
I decided to work on more OLLs last week, after stumbling onto Ottozing’s very good Cubing World video showing all of the dot cases. Specifically, these three:
OLL #18

OLL #19

OLL #20

Here’s a video showing each in slow motion and then full (still worksinprogress) speed:
Some thoughts on each:
 OLL 18: This one took me a while to get down until I realized that it’s basically two wide sunes (OLLs 7 and 8), mated through the r2′.
 OLL 19: I found Ottozing’s execution of this one a bit clunky. He does an r R2′ in the middle, which is essentially an M’. Converting to the M’ sped things up and also made it flow nicely — with the wide r’ simplified into an R’ as the first move of an easy sledgehammer variant (R’ F R F’): Setup (M U) > Sexy Move > M’ > Sledgehammer.
 OLL 20: I learned this one a long time ago, but never could get it down efficiently. I just realized from Nick Rech’s video that this mirror of the algorithm I had originally learned is much easier. Note that he performs a doubleM slice in the middle. But, based on the first moves, your fingers aren’t appropriately placed for an M2. Instead, I execute it as a L2 l2′, which together is effectively an M2. The execution is easier than it sounds, and occurs by turning the left wrist backward and right forward, and then reversing it. Here’s the modifications:
(r U R' U')
(L r) (R' l')(L2 l2') (U R U' R') U' M'
More dot cases to come….