I read for myself mostly because I don't have any opportunities to read for others, but also as a tool for self-improvement and, well... to ask my guides for help. That may sound silly, and as a science geek I can't explain it, but there you have it. Also, I have no idea why, but I do my best readings when reading for myself, and I don't mean "best" as in "bright and shiny".
When I phrase my question right, the answer is usually pretty accurate, sometimes scarily so, even when I don't like the answer. Especially when I don't like the answer. It's tough sometimes, because my cards don't sugarcoat anything...
And if I try to do another reading right after, to get a "better" answer, my deck becomes stubborn as hell. In those cases it's not usual for me to draw the same card 6 or 7 times in a row.
As a rule, I tend to avoid "future" readings for myself. Forewarned is forearmed, yes, but the warning sometimes isn't specific enough for my overactive mind. Here's an example:
A couple of months ago I did a general CC spread, to get a sense of where I was at. As outcome I received the 3 of Swords. That pierced heart scared the hell out of me, because my mom was sick at the time, and I feared something bad might happen. I also wondered if my ex would break my heart again. I kept waiting for *something* to happen and I worried myself sick. After a while I realized the card wasn't referring to an outside event, but to the inner pain I had been feeling since my breakup and refusing to deal with.
Since then I've learned to ask very specific questions, especially when there's an element of future involved: otherwise, a "negative" card can drive me nuts. For example, if I get the Tower as "outcome" in a general reading, I want to know whether my boyfriend is going to dump me or if my house is going to fall down on my head...
I've also learnt the hard way not to ask questions I don't want answered. Sometimes it's not bad to let things unfold as they're meant to (says the Hanged Man in my readings these days).
Sorry about the long rambling post.