This is one of those "an ounce of prevention... " things, as recovering from being straight in can be really tough. As others have mentioned, the rail-first and masse shots are good ones to get a feel for.
On the prevention side, I think what has helped me as much as anything else is simply playing on really tight equipment. On 4.25" or smaller pockets, you run out of offensive options really quickly as your angle becomes less ideal, because you can't simply pound balls into the hole to exploit what little angle you do have. I tend to err on the side of having a little too much angle - I'd rather have to shoot softer than try to force something.
Aaron