I've struggled with that, too. I've found a few key things:
-you *need* authentic ingredients:
-Source your maris otter and crystal malt from an english maltster like Hugh Baird, simpsons, etc. American or German crystal malts from Briess, Weyerman, etc - have a different character.
-Same goes for hops - you absolutely must use UK-grown hops, the American-grown versions of those same cultivars are just different. Good - but not for an authentic-tasting EPA.
-Ditto on the yeast. My favourites are Windsor, 1968, 1028 or 1275. I dislike Nottingham because I feel it's just too clean, and too attenuative for this style.
-keep it simple. Looking through the recipes published by CAMRA (
http://www.camra.org.uk/page.aspx?o=byo), most recipes don't use more than 2 or 3 fermentables total.
-Hop more conservatively than you think you should - especially with the late hops. For a 1.045 OG, look for about 35 IBU's, and 1/2 to 1 oz of hops at 10 minutes, and perhaps 1/2 oz of dry hops.
-water treatment is generally overrated, but depends on your local water quality. A small amount of Gypsum and chalk (1 tsp each) in the mash is probably plenty sufficient.
-age and oxidation - by the time they get here, most british beers are often quite oxidized. Also, cask beers frequently 'feature' oxidation - within hours (or days) of tapping a fresh cask, the effects of the fresh air in the barrel will have an effect on the beer. You might notice that your EPA's start to taste more 'authentic' after 8 to 12 months in the bottle.
95% Maris Otter
5% British Crystal, 70-80L
35 IBU Challenger (or any other British hop you like)
1/2 oz Kent Goldings @ 10 mins
1/2 oz Fuggles @ 10 mins
1/2oz Kent Goldings (dry)
Mash at 148F, ferment w/Windsor
1.045 OG, FG should be in the 1.008 range
It's based on my favourite EPA ever is here, just with a smaller OG and a slightly different hop schedule.
https://www.homebrewtalk.com/f64/first-gold-epa-187410/