There are plenty of strategies for exiting, really could be entire book... I'll describe mine.
Strategies for scalp and day trades exit are different. Scalping is very subjective animal, let me talk about day trades only.
General rule is, hold through slow climb, sell/partial out on vertical stage with volume/pace spike.
As stock moves in my favor slowly I hold it and move stop to breakeven when risk/reward went over 1/1. After this moment I want to sere first spike to dump 1/2 shares into, usually hunting for 1:2 risk/reward. If this first spike was too big serving 1:4 for instance I would dump entire position, or at least 3/4 of it. If stock consolidates after first spike and goes for next breakout I trail the stop for shares balance, using principle: Former resistance becomes new support.
In practice it looks like following:
Stock triggered entry at 20 with stop at 19.75. It paused at 20.25 giving me new consolidation at the resistance level. My stop went to 19.95. Breakout of .25 and stop is breakeven now. Spike occured at 19.45 where I sold 1/2 shares. Stop moved to 20.20 because 20.25 became new support and I want to get out if this support is broken. New consolidation, breakout of 20.50, pause near 20.75 and my stop is moved to 20.45 - the same logic. As soon as stock went vertical I dump another half, or if I feel real strong about continuation, 1/4, trailing the stop for last 1/4 by the same principle.
best regards,
Vad