I have limited equipment to work with.
No lat pull down ... no pull up bars (not that I could use them if I had them) ... no Roman Chair ... nothing hanging ...
Just a bench with a couple attachments and free weights. And I'm using all of that.
In answer to a couple questions/comments:
Yes, I have had sore abs from cycling ... from riding the tandem. Evidently I use my abs a lot for balance on a tandem.
Yes, I am going for looks. I want a strong core too, of course, but I'd like to look it. I've kind of got the bodybuilding bug again. Now that I'm back down to my usual size, I'd like to bulk up a bit and it has begun. I've got biceps! And in the abs area, I've got a 2-pack.