Generally 'quality' foam brushes work well when using HT; although, high quality 'soft' large artists brushes work best followed by lightly and quickly 'tipping' with a dry foam brush. Laydown should be the same as varnish - full brush pulled in one direction only and at a low angle with light pressure, just like varnish you want it to 'flow'. For superb flow-out and leveling on the final clear coat, the use of a Preval type self-contained spray-bottle is ultimately the 'very best'. Preval Paint Spray Gun Kit
Acetone or Lacquer thinner, etc. are 'verboten' when using HT, so is the prior use of any 'stripper' unless you are willing to wait an immense amount of time for the MEK, etc. to outgas away.