Forgive the structure as I'm answering from the phone as I've been out of town,

1. For etc
   A. I would have not took that buy.
   B. The clear base is 56, 10-15% lower than this would be a good start to buy

2 For nbt, this is a little harder and one I still struggle with
You could put a base at 41 but the safer base is 38 obv. Again 10-15% below the base is a good start, but try to go a little further back in chart history to see how some of previous drops happened.

Now if bounces not working in your favor, you could hold on and wait but understand you're risking further drops. I prefer to not hold on and sell some on every bounce after 3 days not getting the results I desire even if it's for a loss. In the future, I'll blog about some losing trades I had with mistakes I made

For future trades, try to sell on every bounce instead of waiting for the one big return...you don't have to sell all, you could always hold on to some pieces in case those big gains happen. Like in etc, you could have sold some at 64-65s. Better to complete a lot of quick 10-15% trades then hoping and waiting for the occasional 25-30%. Also Psychologically, this will work in your favor to feed the reward of completing lots of good trade. This will come with experience.
Hope this helps, and good luck.

I'll be back with more trades of the day once It return home next week.