I drew trend channel lines but Ican't foresee trend reversals

Rick over at http://www.forexnewstrader.com is a master scalper. He scalps 1 min and 5 min candles, news events and serveral other strategies. Check him out.

It really depends also on the time frame you are looking at. Try the triple screen method as recommeded by Dr Alexander Elder in his book "Trading for a living"@http://geocities.com/lcming/Forexbooks - an excellent book btw on the pschology of trading. Anyway look at the next immediate time frame before and after the one you are monitoring. Say if you look at 4hr, then before and after would be 2hr and 8 hrs.

For reversal i like to use the candlestick reversal signs. I find candle sticks reversal signs are pretty accurate and appeals visually as well.

Combine maybe also with an extreme stochastic either OB or OS as the case may be. For more forex signals @http://www.geocities.com/lcming/Forexsignals