How to know when you're falling victim to "over thinking" and "paralysis by analysis"?

In my life, I've been able to experience the extremes of being "too impulsive" and then at the other end, being "over analytical" but I don't know when I've gone too far in the "over analysis" territory. I want to make sure my decisions are well thought out and now I'd like to know how to know "when I've thought this decision out enough and it's time to make a decision".