I was getting quite disappointed with the hoppiness of my brews, even with 250g of dry hops until I changed my technique recently. This is based upon a few suggestions I've picked-up from other users here.
I now ferment short at 20 litres (this also avoids foam-overs)
100g of Dry hops in a nylon straining bag (weighted down with a spoon) for the last few days as usual.
I then squeeze every last drop out of the bag into the FV by hand
I then pour those used hops into a cafetiere (aka a french press)
Add boiling water straight from the kettle and stir for a few minutes to make a hop tea.
Using the same hops, I repeat the hop tea process a few times until I've collected 4 litres of green liquor.
Finally, pour the hop tea into the FV to make-up to 24 litres.
After bottling, this gives me 22 litres of very hoppy beer.
Next time you throw your used hops into the bin, just take the time to enjoy those beautiful wasted aromas, its really surprising how much more flavour they have to give, even after being rinsed in boiling water a few times.
One disadvantage of this method is that it prevents the accurate measurement of specific gravities, but I prefer to worry about taste than decimal points of alcohol content.