I have a simple, but mostly very effective strategy
I bet principally only at betting exchanges because there you
a) get better odds than at traditional bookies (in 90% of the cases) and you
b) can build perfect surebets due to significant odds fluctuations
Odds fluctuations are the main basis of my strategy. One prerequesite is that the bet is offered in-play (live) and that you can also follow the match live. A further condition is that it is a match where exactly one (1) goal has been scored, meaning the current score is 1-0 or 0-1. It would be good if at the time the favourite is leading.
When you watch the match, shortly before half-time you often see that no more goal will be scored before the break. Sure this can happen at any time, but my observations have shown that during the last minutes both teams often try to 'get into the booth' without conceding a goal.
Then you go to the betting-exchange and BACK 'under 2.5 goals'.
Ideally, this should be done at about the 40th minute of the match. The odds are often still quite high - e.g. 2.60 in my last bet on AC Milan - Lecce when the score was 1-0 in min. 40'. Now sit back for some minutes and continue watching the game. In my case both teams really tried to get into half-time without conceding a goal.
Now you LAY 'under 2.5 goals', meaning that you bet against it, which means you will have a definite profit in both possible outcomes. Every punter dreams of such situations.
The profits are not as small as you might think. In the 'trial time' of that betting 'system' I started backing with only 4 quid, but then increased my stakes.
I determine the amount to lay in order to have the same profit in both possible outcomes. In my example with AC Milan green £0.70 stood on both sides.
This way - with a £4 stake you get £0.70 to £1 net profit for sure. This is 20% of the stake - which is enormously high. Logically, with higher stakes also the definite net profit increases, too.
Have fun with my betting strategy.