watching back a Video of yourself casting is a great tip , slow motion is even better ( most phones have this function ) you can break down each individual part of the cast & really see what huge differences there are when you get it right & wrong & really see what your doing rather than what you think your doing .
150 - 160 should be achievable without a leader 15lb straight through.
Just practice is the best advice & try a selection of leads some distance leads really wabble through the air , some are better for cross winds etc .