The Tips in detail

 "Do not dump any of your scenery-files."

The time will come when you stumble over a problem and start thinking »I already did this once...«. Even if your scenery is not worth to be rendered and mentioned anywhere, you might want to reuse it in days to come. Doing this you will build up your own collection of tutorial scenes over the time. But carefull here: don't over-recycle things too much! You won't learn from old mistakes by redoing them and creativity means much much more than simple recycling.

Be carefull here in terms of copyright. If you built objects for a certain project / client, you might not be allowed to keep any files related to that project. Refer to your contracts for this task.

Having the designing and building process of scenes or objects documented in a bunch of files showing the states of progress might come handy when it comes to lawsuites (may this not become true for you!) concerning copyrights.