Whatever your strategy, always try cover yourself. If you're placing £1 on a bet that looks like a long shot, and although 1 in 100 times it may come in and make you a fair bit of profit, place a bet on something you're think has a good chance of coming in that will win you that £1 you're likely to lose on a longshot. Let's look at some examples :
1. You put £1.50 on a Lucky 15 longshot. Lucky 15s are unlikely to win every week, but when they do you could be making a large profit. So, you expect the bet to not return anything. So, place £1.50 on Liverpool to win away at Leicester at 1/1. If Liverpool win you've made the money you've written off on the speculative longshot.
2. You've got £10 to bet, and want to place it on something reasonable that has a good chance of winning. Chelsea are playing away at Middlesbrough at 6/5 and Leeds are playing away at Southampton at 11/8. Instead of putting your whole £10 on one game, don't put all your eggs in one basket. Instead use the higher odds game as a cover, putting a smaller amount on this game. So, in this case, Leeds are your cover, and Chelsea your winner. If both win you've made a nice profit. Put £4.21 on Leeds at 11/8 (£10/((11/8) + 1)), which will win you exactly £10 if Leeds win, and put the rest - £5.79 on Chelsea which will win you £12.74, a small profit if only Chelsea win. If both win you've got £22.74 from a £10 bet. You could have placed your whole tenner on Chelsea and lost the lot on one game.