Many roulette strategies can be found on the web and youtube. Common known column betting, row betting, line betting, split 17 betting, etc.... None of them win in a long run.
I play my own way, can't call it strategy, it's more on monitoring, not only the 36 numbers + the Zero, but also how other players play, who is the big winner and loser on that table, how's the dealer's habbit of throwing the ball? Take 3-5games (15mins or so) to see the above.
Me only go for 3 games, max 5 games, change 1k color chips. Each bet $300-$350. Win or lose, 3games, max 5games. Can't win big from roulette and need thinking. I don't quite like thinking when I am in casino, so I don't play often.