I have said this many times, but a good strategy begins with good money management.
If my strategy produces 90 winning trades out of a hundred, and I make $1 per winning trade and lose $10 per losing trade, I make a $10 net loss. On the flip side, if I win 10 trades out of a hundred, and I make $10 per winning trade and lose $1 per losing trade, I make a $10 net gain. All I've done is limit my losing trades to $1 each, and let my winning trades run to $10 each.
I know this is an over simplified scenario, but it does highlight the power of money management. If you know the historical win/lose ratio for a given strategy, and the average amount won in a winning trade, you can plan ahead. If you have a 30/70 win/lose ratio, and your winning trades average $20 each, on average you'll win $60 in every 10 trades. If you want to ensure a net overall profit you'll need to keep your losing trades under $8.50 each, and preferably much less!
Learning about money management is worth every bit of effort you put in. Theoretically speaking, good money management makes losing almost impossible!