As one of the chief Decisions = Life proponents lurking on this site, I guess I should probably throw out an answer here...in part because I think conscious decision-making is one of most under-rated yet most powerful "tools" that we have at our disposal to transform our lives...but mostly because I haven't ranted and raved about it for a while :)

Here's a principle worth bearing in mind...

The way to get better at doing anything is to do it more often

While that insight is probably not worthy of the Nobel Prize For Insightful Quotes, it's a truth that seems to get overlooked time and time again.

The "do-ing" (in doing it more often) does not have to be physical do-ing either. It equally applies to molding bad-feeling thoughts to better-feeling places (for spiritual/manifesting purposes) or, in your case, it applies to decision-making.

So here are my suggested physical steps for you to become a more decisive person...

Step 1: Make More Decisions Every Day

Step 2: Do Step 1 :)

I tend to 2nd guess myself a lot even after a decision has been made. I also keep thinking of all the "What ifs" if I had chosen the other option.

If you are second-guessing your decisions then you are sapping the energy out of yourself that the decision-point originally summoned within you. So it is self-defeating. It's not actually the decision you make that matters, it's the fact that you made a decision.

What might be happening for you is that you are not considering something to be a "decision" unless it feels like it matters to you in some way.

If you are sitting on a train and you decide to sit in a particular seat on the train, do you then spend the whole journey wondering if you should have sat in a different seat?

Or, if even that feels like too big a decision, if you take a stride while walking somewhere, do you then spend the rest of the day thinking if you should have made that stride a bit longer or a bit shorter? Or if you scratch your nose, do you then wonder if your scratching finger should have been at more or less of an angle relative to the rest of your face?

All these seemingly-trivial activities still involve decision-making. You probably make thousands of these kinds of decisions every day already without even realizing it...because they are at a level that you feel doesn't matter to you.

If you think about it, you'll notice there's a point at which decisions feel trivial and not worth your attention - you just make them - and, beyond that point, you probably start the second-guessing process.

But if you are making decisions constantly and consciously all day, where are you going to get the time to second-guess yourself? ...because there's a new decision coming up all the time :)

I used to (and often still do) put myself in deadline-driven situations as a way of sharpening up my own focus and decision-making processes. When time is genuinely pressing, you don't have time to second-guess...you get forced into making a decision and then dealing with the consequences of it :)

Of course, you don't have to go to extremes like that.

If you just consciously Make More Decisions Every Day about anything and everything, you will just naturally expand your decision-making "comfort zone" because there are too many decisions for you to worry over.

If you find that your second-guessing is driven by a fear of making bad decisions then that's easy enough to neutralize if you use some clearing process (e.g. EFT, Focus Blocks or whatever).

Or you could just "re-frame" to yourself what making a "bad" decision actually means...I used to have this quote as my computer wallpaper...