Finishing is about practicing short balls - putaways and approaches. And solid net game - putaway volleys and overheads.
Tactics start with recognizing "green, yellow, red" balls - attackable, neutral, defensive for you. You should have clear vision:
- What you want to do to survive an neutralize when pushed - usually hit high and deep unless he's at the net
- What you wnat to do against neutral ball - hang in the rally waiting for opening, working him off the court a bit, or hitting to the zone where he doen't like it and tends to make UEs or give you attackable balls
- What you want to do when you earn attacking opportunity. Will you hit DTL and come to net? Or go for wide angle first? Or bash his BH with I/O FH?
Anyway, you don't think to end points from "red" or "yellow" balls. Even going for passing shot, you are ok to trouble him and get a pop-up volley or weak OH, not mandatory clean pass. If you don't want to hang in rallies, take serves and returns as setup opportunities, it's best moment to ramp it up and take control of the point - much easier and promising than trying to advance against good neutral rally.
To sum it up:
- Be mindful of what's your situation on every particular ball you get, act accordingly
- Use what he doesn't like to get attack opportunities. Use your strength to get attack opportunities
- Practice playing short balls, approaches and volleys a lot so that you are happy, confident and consistent every time you get an attack opportunity
Here's video, from 14:15 he calls out type of ball loud: