
Tenuki from the lower left is fine in many cases, but tenuki for this move in gote is kind of small. White already has an overwhelming presence on the left compared to black. You could consider trading C3 for J3 first, but you should probably look at approaching the top right corner to keep the game relatively balanced and simple.

This move is too early. You should be able to profit from attacking it.

Good.

Not so good, IMO. Maybe follow up with another knight's move at H12 to keep pressing black into your stones. It's worth thinking about G12, G13, and maybe H13 too, but you want to keep black confined against your group, not force him into the center where he can remove the pressure on his group.

This is a bit wishy washy. At least hane. When you push for a move, and then hane, black is stronger and can deal with it better.

High is for special situations only. What are you worried about if you play the knight's move approach? On a broader level, can you continue your attack profitably instead? Would it be better to approach on the right side and leave black with a small corner?

This is aggressive. There's aji for white to live in the corner without this, so black should reinforce in some way. On the other hand, maybe you want to invade later and should leave this open?

I think I would prefer jumping to P12 or the like directly. Then you can still invade the corner if black doesn't reinforce it, or leave with sente to deal with the bottom.

This is a big move, but it's also a move that says "I've won with this and don't need to attack your group." To stay in the game, you need to figure out how to make points by beating up black's center group here.

Under normal circumstances, this is a good move, but white's already behind and can't afford to play this way. Once black takes sente to settle the center group, white's behind on points without a clear way to catch up.

This is a shape point, but it's not the right time to hit it. Black doesn't need to make eyes if he can connect out on two sides, and black has decent eyeshape anyways. Plus, it's easy for this stone to come under attack. You could consider F12.

Great idea.
:w108: F12 works even better now.
All in all, at the end, assuming the bottom group lives, white's not doing too terribly.
I'd be curious to see your 'territorial' games. Why did you get slaughtered? Might be good to find out what didn't work and why.