3D Printer - Some Lessons Learned

I am sure that I am no where near done having my printer learn me lessons but thought that I would take a minute to capture some of those learning's to date:

• Seems obvious, but, turn things off when making hardware changes!   As in unplug the power and the USB connection!
• Probably obvious to someone that knows electricity, but, unplug the printer before soldering something (like a control or power lead) that is connected to the printers electronics!
• When doing calibration prints keep a careful record of each print and the conditions for that print.   You might even want to go so far as to save individual config files for the slicer you are using.
• Don't mix PLA and ABS in the same nozzle.  I am not completely sure this is backed by any one else but I am convinced that I had a mega clog as the result of this practice.
• "ABS Goop", which is some ABS dissolved in acetone, makes a good bed prep for printing PLA.
• A clean bed results in a clean printed surface!
• PLA is a lot easier to work with than ABS.  In my case I had much less issue with warping, adhesion, and as a bonus everything was faster given a lower bed temperature.
• Printer enhancements for ease of adjusting the level of the bed early is highly advised!
• Once you have done the above you can do a rough adjustment of height using the piece of paper method and then print a bed leveling exercise to get the rest of the way.  I print this file pausing to adjust the overall bed height then resuming while often adjusting corners with the printer running.
• Timing belts should be tight.  This is another thing that might seem obvious but I ran for quite a while with belts that were a lot looser than they should have been.

It feels like I am missing some things ... which I will come back and add as I remember them.