How do I maximize my chances of being summoned in Blades of the Darkmoon/Blue Sentinels?

It's not just you, a lot of people have been having issues getting summoned as a Darkmooon or Blue Sentinels, and folks are pretty confident it's a bug, despite FROM saying otherwise. The good news is that there does appear to be a work around you can use, provided you're on PS4 or PC. You can find the links to the solutions here.

For PS4 folks have found that making a brand new account fixes the issue, although no one is sure why. Definitely worth a shot though. For Steam you need to make a new account as well, and then set up Family Sharing so that you can play Dark Souls 3 on the newly created account. You can transfer your save over to the new account) by replacing the save files in the new account with the ones from the old account, but some folks have reported that transferring the save didn't work, so you may be forced to start a new account if you want to do Darkmoon/Blue Sentinels coop.

So, in short, the whole thing seems to be broken and the only workarounds are kind of terrible, but there are workarounds. Once it is all working the range for being summoned is (source) (Host = Way of Blue player, Summon = Blue Sentienl/Darkmoon Player):

Host's Level - 10 - (Host's Level * 0.1) < Summon' Level <Host's Level + 10 + (Host's Level * 0.1)

I am about 250 +/- NG6 and have been using Darkmoon since I got it on the first play through, almost never removing it. I think I am ranked in the Darkmoon Knights book at around 450. I get summoned regularly, but lately it has tapered off.

I will say that when I am summoned, I never know which bonfire area it will be in: I have been summoned into the endgame areas while running around in an NG run on high wall, and vice versa. So I personally have not noticed any correlation between where I am and where whoever "called the cops" is.

I do think the higher level players do not run with the Way of the Blue very much, but it also may be a reduction in the player pool: when I first got it was within a day or so of release on PC and at that point one could get summoned as a phantom within seconds of dropping a sign down. I would get Darkmoon/Sentinel summon every minute or so during peak times.

I used to get summoned a lot without being embered and I run around embered almost 100% of the time now and I am not swamped by invaders nor summons, so the pool is probably reduced both by volume and also my level, and it is unclear to me if ember status has anything to do with it.

It it pretty normal now that I occasionaly have to take off the Covenant for a half hour to avoid being re-summoned into the same fight club or game multiple times. This, to me, indicates that the pool of available people is very low.