1) First do some homework. Read up more on other teams. For example, go
www.livescore.com, click on the team on match day and see their past performance. That's the least bit you can do.
2) (Winning streak scenario) Know why people always lose money in soccer? Because when they win $100, they bet $200 on the next game. When they win again, they bet $300, then $500 blah. Eventually it just takes one match to lose all the money they earned previously.
Tips: Always be consistent with the amount you bet. Eg $100 all the way
3) (Losing streak scenario) However if you are losing, you can try the above method. So you lose $100 in the first match, bet $200 on the second. Lose again, bet $300. This method of betting is illegal in casino: the banker will stop you from betting anymore by making it MINIMUM BET : $1000 or something but you can probably do it outside a casino. JUST MAKE SURE YOU HAVE ENOUGH FUNDS TO KEEP SUPPORTING the losing streak until you win and recoup your losses at least.
4) Another tip would be to check out
http://fun.asianbookie.com/index.cfm?top20=1. You may just win money betting the same as those top people. (in the long run)
Of course there are lots more tips but this are my general ones.