I lower the dumbells until the bottom touch the line, where it feels natural. I don't force myself to go lower and I don't pause at the bottom. I assure you that I don't do partials reps
More info about my lifts:
About my triceps strength, they are definitely the weakest link in my bench. The weird thing is that I am relatively good at skullcrushers (I can do a few reps at 125lbs and I max at 135lbs) (I don't do that often because it is hard for my elbows) while they are weak at pressing. My CGBP max is about 245 and it is hard to get my triceps working while doing it. That is why I do partial CGBP from pins.
My shoulders are not that weak compared to my bench.I don't have any conventionnal exercise stats (I train at home with a low-ceiling) but I can max at 185 on sitting overhead press from the lowest pins I can. I can do 1-arm leaning-away lateral raise with 45lbs with strict form. That doesn't say much I know. 1.5 years ago my standing military press 1rm was 205lbs and my bench was 225-235lbs. I have wide clavicules also if that means anything.
My forearm are somewhat long and I know it may create a better lever for exercise such as skullcrushers and curls.