You need to give some room for the stock to move. Otherwise it's bound to happen. (Scalping is an exception)
For example, in my intraday set up, I keep 2% SL.
Here's what you can do.
1. You should first define how much loss you can bear per stock. Say, you can lose maximum Rs. 100 per day.
2. Now, calculate the capital required for you to lose just Rs. 100. After calculation, we found that the capital is 5000 for you to keep 2% SL and lose Rs, 100.
That's how you do money management.