LFH/ Long positions using MACD histogram, long EMA and short EMA

Disclaimer: I'm a noob.

Hey there!

I'm trying to implement a script which enter market long position when long EMA crossover short EMA and MACD histogram is positive and histogram at T time is lesser than histogram at T-1.

And when short EMA crossover long EMA, plus MACD histogram is negative and histogram at T is greater than histogram at T-1, I want the script to exit market long position.

Now, I have something pretty close to what I am looking for. What I am missing and can't figure out yet is:

• How to moderate entries, ie. I would like it to enter positions when trends are really interesting not just every time the conditions are fulfilled (same for exits) as there is way too much positions
  
• I need to find a way to exit appropriated positions.