Trend line:
Once a trend line has been broken, the price will fall back to re-test the broken trend line. Then when the price goes above the first reaction high after the breakout - that is your conservative buy signal.

There is no way to determine which way a breakout will go, but when it does, the move will be significant. A conservative estimate on how far the breakout will go is to take the distance of the widest part of the triangle, add that distance from the point of the breakout.

Gaps: Take the distance of two gape, this will give an estimate of where the market will go next.