I have found that as I've gained more experience, my ability to rapid-prototype has gone down - it's extremely hard to break out of the habit of doing things th

I have found that as I've gained more experience, my ability to rapid-prototype has gone down - it's extremely hard to break out of the habit of doing things the 'right way' and go back to doing them 'the fast way'. (On the other hand, my prototypes actually work). Get to know some basic building blocks in one language really well (e.g. simple CRUD patterns in PHP), then design and build everything around those. It'll be messy, but rapid prototyping is often not the place for elegant architecture. Experience is invaluable when you're prototyping something that requires a lot of knowledge (e.g. APIs), but for most web apps, most things you would want to prototype can done very quickly with limited knowledge. If you're stuck on getting started, just grab some example code (App Engine has plenty) that does something close to what you want, then hack away at it until it gets closer, then let error messages and satisfaction drive you the rest of the way.