continuing my point from this topic, which which has posts you might also find useful, about good shape, when the opponent plays tenuki with a bad shape, it is always a good idea to punish them for it, instead of letting it slide. Here is a possible result:
Another example a bit later, you are both playing cuttable shapes (A, B and C, D) nearby each others’ stones. Your opponent cut you immediately and got the better result in the real game, however:
However, let’s say you had cut immediately instead:
Now it is your opponent that is in deep trouble.
Even if White opts for this:
Black is still going to win most - if not all - of these fights.
Most probably there are tesuji that higher level players can deploy to these sorts of, but for our level, as long as you go for the good shapes and go after the opponent’s bad shapes, that is more than enough to bring you great results 
P.s.
Black can also kill the group directly there, now that I am looking at it. Here is a possibility (again there might be some tesuji to save it, but if there is it is not something I’d find during the game):
