I seem to get pretty good life out of mine, these are some things I do. I only have experience in two products so far but common sense tells me it's helping.
If dripping, don't over do it, three drops is more than enough for 6-8 drags on a 401 sized atty.
On my 701 ( cigar ) I use the carts, they are huge and will last along time but I check the wicking material every 1/2 hour or so if I'm doing the constant vape thing and top them off with a few drops from a bottle if they look dry. It does not mean you will never have to refill the cart from scratch ( the fluid in the cart starts looking dark brown and seems to be thicker in consistancy, this can't be good for the atty ) so I go ahead and clean the cart out and start from clean fluid at that point.
When I refil a cart I take the time and get the majority of the crap out of the atty too ( I'd guess it is brown and thick too ) , just hold a paper towel against the bridge of it and blow from the other side ( Remove battery for this ). When you aren't getting anymore juice on the paper towel, you're done. Place 3 to 6 drops ( 3 for small atty's, 6 for huge ones, 4 or 5 for those tweeners ), put a new cart on, and set it on it's side for 5 min before vaping.
If you have a penstyle/401 check the area between the cart and the battery frequently for juice, wipe up with the corner of a paper towel if you see any, I've seen quite a few folks have battery problems and it seems that dripping a conductive juice inside of them is bad ( imagine that ). It's my guess that juice also lowers the voltage to the atty causing an incomplete vaporize of the juice leading to clogging conditions. I swap batterys long before they are dead to help vapor production.
While you are vaping, pay attention to how much vapor it's producing, if the vapor starts dropping off, stop and investigate, atty's starting to get clogged ( quick blow on the paper towel trick ), juice between it and the battery ( paper towel wipe ) , dry cart ( top off or clean and refil ) , low battery ( swap it out ) are the ones that seem to be the most common and the easy ones to fix.
I know the damn things are fiddly ( at least so far in my experience ) but keeping everything clean and tidy ( no over/under juice ) seems to go a long way in the life of these things, hey it's a small price to pay for not putting all that crap in your lungs nor paying the outragous tobbaco taxes.
I haven't got to the point where I need to ust some kind of acid to clean off the coil on any of mine yet, I'm kinda curious on how long they are going to last without doing that just by cleaning them as I have been doing. I'll let you know when one of mine dies outright.
My Prodigy will probably ship today.

( sorry I had too )