I'm cheapskate.
My tweaks are usually free, or very very low costs.
Let's see.... The free stuff:
- remove extraneous metallic objects from the proximity of my audio system.
- space out distances between each audio components.
- place source and pre-amp away from power amp.
- throw away the refrigerator.
- remove wired telephone from the house.
- shut down and unplug wireless router when listening.
- remove clocks and watches from listening rooms.
- stop wearing watches and metallic ornaments on the body.
- remove the 13-amp fuses from any power cords using the uk standards AC plug.
- all household appliances unplugged
- all AC outlets with on/off switch that are not in use to be switched on.
- ground the chassis of my audio components internally (making sure the earth wire is correctly oriented in the right directionality).
- short the plus and minus terminals of unused speakers if they happen to be in the same room.
- hydrate the room regularly either by opening the windows, or by placing cup of water in the room.
- refresh the motor of turntable before playing every side of the vinyl record.
- refresh the cd transport and DAC before playing every cd.
The tweaks that cost money:
- leave the vinyl or the cd on the shakti stones for a couple of days.
(Shakti stone is kept far far away from audio components)
- spray vinyl records with tap water and spin dry.
- if encounter any issue of imaging skew left, run the cd disc under tap water and drab dry with tissue paper.