Back on a chosen selection (favourite).
If the bet win, divide the profit by a specific number (for example, 4) and add that value to the next bet. For example, if you backed £10 at 3.0 and win £20, then you back 10 + 20/4 = £15 in the next 4 games. If the profit has been lost in those 4 games, revert to the initial bet size.
If however another bet was won before the previous profit was lost, add the new profit to the existing one and divide it by 4 again, repeating the above steps. Thus another cycle will be started.
Continue this until the profit is lost, or until the maximum profit is reached, after which reverse to the original bet size.