Well i heard somewhere (i dont remember where) that thinking about something as you fall asleep will make you dream about it, and will help improve your skills.
The example was: A doctor had a patient who doesnt play videogames play a skiing game, then that night he instructed the patient to think about the game as he fell asleep. The patient had a dream about walking through thick snow. The patient remembered that if he walked in someone elses footprints it would make it easier. The next day when he played the game again the patient got a score 30% better than the first time.
Somehow thinking about walking in someone elses footprints made the skiing game easier.
When i first heard this i laughed but then i decided to try it and although it may take a few tries to actually dream about something even remotely related to the game, or even remember what you dreamed in the first place i truly belive it works.
I do this with alot of games and have gotten very good results. Forza Motorsport 3, Battlefield Bad Company 2, Halo 3, Halo ODST, Split/Second, Command and Conquer 3 Kanes Wrath, Oblivion, Fallout 3, Mass Effect 2, Gears of War 2.
Ive found that (at least with me) its not a noticeable difference, well to decribe it better i dont feel like ive gotten any better, i dont know something that i didnt know before, when i play i just DO IT. Its sounds wierd i know but when i started playing BFBC2 after 3 days i was steadily averaging about 8-12 kills with maybe as many deaths then i decided to try to dream about it to see if it would help. I had a dream about trying to cross a bridge that was collapsing, in order to make it across i had to move as fast as possible without putting too much wieght on one spot on the bridge, the faster i moved the less stable the bridge became and the closer it was to falling. So i adopted a careful pace that would keep the amount of my body wieght on the bridge down but would get me across the brigde as fast as possible.
The result was an increase in my average SPG to 25-28 kills and 2-10 deaths.
I havent yet figured out how the dream helped but it was instant. The last game i played the day before i scored 9 kills and 13 deaths the first game the next day was 19 kills 7 deaths with the exact same weapon loadout. That scored remained consistant within 2-3 kills/deaths the whole day despite switching rooms several times (to those who would say the ppl i was fight just sucked).