Few tips that I have learned since I built my HERMS.
Pump water through your coil prior to adding the grain - This helps alot with reducing stuck mashes.
I keep my HLT about 11-15 deg or so warmer than my intended mash since you will loose heat from the wort transferring. 
Get some insulation for your MT.  I use reflectix bubble insulation.  Cost is about $20.
Consider recirculating the whole time instead of when the probe reads a certain temp.  The mash has different temperatures everywhere and circulating helps reduce the variance. 
A pump or manual stiring in the HLT will help with stratification.  A pump is obviously nicer and helps with consistency(you can just set the controller and forget it)
Get a "T" so that you can transfer to your kettle without having to deal with the moving around your disconnects.  I wish I would have bought more "T"s when I first made my system.
I personally havent had issues overshooting in my HLT, but I use a bucket heater or two to maintain and raise the temps.
				

 Cheers to the MI crew.
  Cheers to the MI crew.








