How to minimize the loss of time/effort/money when working on bad ideas?

I often have an idea about something, I get too excited about it and start to work on it, only to later find out that the idea isn't as good as I thought. — How to avoid/reduce mistakes like these?

Talk to potential customers early, even before you begin building it.

Give your ideas a marinating period before you do any work on them, say a week. But during this time vet the idea with potential customers.

After the marinating period and based on the responses you received you’ll have a better idea if it’s an idea worth tackling or not.

ship quickly, ship cheaply, ship smartly. i am planning on writing something on this, so that i understand what that means. will link here when it is done. no ETA, just yet.

You've got the process backwards. Like many makers by the way.

What it sounds like you're doing now is building a product, and then hoping it's something people want. That's very risky. There's a good chance you're building something nobody wants.

You want to flip your process around. Find out what people want, and then build it.

How do you find out what people want? There's many ways. Talking to potential customers is probably the easiest, although maybe scariest as well. Listening in on their conversations (e.g. on Twitter, help forums, etc) can work too. Even quickly prototyping a product and showing them can be a way to see what their needs are, but you have to be very careful not to invest too much time fine-tuning it. Don't confuse your validation prototype for your actual product.

Next time you start building something ask yourself: does the customer want this? how can I find out? how much time am I willing to risk building something nobody might want?

Take small steps. Get feedback. Iterate. Take more steps. As you develop more confidence of what the customer wants you can start taking bigger steps.

Don’t do something just because you think it will make you money but you don’t really care about it. Find a problem/issue that you will love solving for the next 10 yrs. Don't do Make fast & break things. Build something that scales and you deeply care about it.

If it's something you plan on spending months on hoping it will return $$$, make sure you validate. If it's a little side project that you will build to learn a new programming language, api or framework just go for it and build, as you will learn a lot which is super beneficial whether the end project is a success or not - and have fun.