I've been working on an idea with a while now and plan to go full startup come the summer. However, every now and then I'll get another awesome (at least, it seems awesome) idea. I'm never sure what to do when I hit this crossroad.
Do I keep working on my current (more developed) idea? Do I shelve the new one and keep working on the older one? Do I take a pause from my current one and develop my new one?
Based on experience, what is the best course of action in these situations?
Haven't you answered this question for yourself by writing it above?
If you come up with new ideas all the time, and you dump the idea you are currently working on for the new one, you will never accomplish anything. You will always be dumping something you have invested time and effort into, for something brand new.
Write down all your ideas. Evaluate which one you want to do first, based on whatever criteria you want to use. When you get a new idea, add it to the list and prioritize it, as you did previously. But remember that whatever idea you are currently working on should get much higher priority than any new idea.
Once you have accomplished something and have a few products, you might make an exception for a truely brilliant and time sensitive idea that you get while working on something else. But until you have a proven track record of actually finishing a prodject, don't let a new one intrude.
I use weighted decision matrices (I actually just used one today to figure out what project to pursue).
Start off with a table, and to the left side draw one column and title it factors. Then make additional columns to the side for every idea you have. Now write down all the factors that are important to you, e.g. How big is the market, how fast can I finish the product, how easy is it to market, etc.. After you've listed all important factors, weight each factor from 0-10, 0 being it is not at all important for me to 10 being it is very important. For example, if market size was pretty important to you, you would have one of the rows in the factors column with the value of "Market Size (7)". Add weight to all factors.
Now for each of your ideas, go down the column and grade each row, 0-10, on how well it performs on the given factor. For example, IdeaX has a very large market so I will put a 10. IdeaY has a large market too but somewhat smaller than IdeaX so I will grade it 8. Do this for all the ideas on all the factors.
After this, you must grade each factor overall (weight * grade). Since we said market size weighed 7, and IdeaX had a grade of 10, IdeaX scores 70, while IdeaY gets 56. Do this for all the ideas.
Now add up all the scores of each idea and write them at the bottom of the columns. Whichever idea has the highest score is the winner.
Factors IdeaX IdeaY
*Market size (7) * 10  * 8  *
*Finish Time (9) * 5  * 9  *
*Mrkt Diffic (4) * 8  * 3  *
RESULTS: 147 149 -- IdeaY is the better choice
// Note that marketing difficulty and finish time judge how easy / quick it is to do said tasks.
// Higher value means easier / quicker.