You can always experiment with length. Hair is one of those things thats very unique to a person so my advice might not apply perfectly everywhere. Hope it works out
What model? I have ran a couple into the ground. Philips was terrible the whole time, but got worse and I eventually got a different brand. My Braun silk epil 9 has been great, but required a head replacement at some point. These epilators wear out such that they don't grab as well, just yanking on the same hairs and not actually plucking them - ow.
Tips...
trim first. Epilating full length hairs enables the yanking-not-plucking since it's most effective at plucking when the tweezer is directly above the hair it's grabbing
be clean and not sweaty. Epilating in a hot house is really painful.
though they're marketed for wet use, I've found this results in a bad trim and not an epilation
don't try to mow areas like a lawn maximizing hairs per pass. Start at the edges of hairy areas and overlap it as little as possible with each pass unless you can stand more. If you try to make use of the full width of a 1.5" head it's gonna be a bad time.
Upkeep every week or two is about 10% as much hassle and pain as upkeep every month or two. They don't all grow back at once so density is greatly reduced when upkeeping before full regrowth occurs