How to catch a high CP feisty Pokemon?

If you want to catch a feisty high CP Pokemon that is likely to escape many times after capture just because it can then Razz Berry is your friend. Feed the feisty Pokemon Razz Berry to calm it down then throw your Pokeball to capture it. It is possible it might escape again even with the use of Razz Berry. There is no guarantee of absolute success here, but at least using Razz Berry decreases the chance of the captured Pokemon escaping. If the Razz Berry effect wears off, feed it again and don't skim on Razz Berry if you want the high CP Pokemon badly.