Should I vary the first layer height
Up till now, I've tended to scale my first layer according to the print quality, so a 0.12 mm first layer for a 0.08 mm print, and 0.28 mm for a 0.2 mm print.
After changing to a PLA which isn't sticking well, I'm wondering if the first layer is best determined by the printer/tolerance/material, rather than the overall print quality settings. Am I going to get more predictable results if I stick to a 0.12 mm first layer regardless? This is with a 0.4 mm nozzle on an Anet-A8.
I made more negative experience for 0.4 mm nozzle and 0.2 mm layer but 0.28 mm initial layer. Change it back to 0.2 mm solves all adhesion problems for me. (Tested on Anet A8 and Ultimaker3)
@SeanHoulinhane If this is the solution to your problems and you want to, then I could post this as answer. But till then it is just a litte tip ;)
I always print my entire model with the same layer thickness throughout, regardless of material.
Default settings for first layer height in Slic3r Prusa Edition print profiles regardless layer height is 0.2 mm.
If you need to improve bed adhesion then try tips from this video 3D Prints not sticking anymore? Watch this! 3DP101 by Maker's Muse. It's about using glue stick and spreading it using paper towel and isopropyl alcohol.