there is no "best way"
there is a way, that within YOUR system, YOUR trading methodology, and YOUR risk tolerance, and YOUR risk/reward setups, works.
obviously the BEST exit is when you exit a long at the top, and a short at the bottom
that is also an impossibility. so get over it
PERSONALLY, within my setups, system, etc. for the YM i have a very specific strategy.
my optimal size is 3 cars. the first two exits (for the first 2 contracts) is nondiscretionary. it's rule based.
the third is discretional. this is the best of all worlds FOR ME. it results in high net %age winning trades .
i think that one exit strategy that is right for most traders and most systems is regarding losses.
imo, stops should be set UPON entry. iow, if u don't know what yer worst case exit scenario is, you shouldn't enter.
i can accept some flexibility in my exits for profit (some), but none in my stop loss. too much ego and emotion involved to play with that. i never increase my stop, although i will sometimes decrease it based on my system
also, for index futures (not for stocks) i will never add to a winning position. doesn't work for me. i will scale out but never add.
risk management and trade management is the most important thing
entry strategies, frankly, are less important than exits.
imo