Dropper post lube

I work on the theory that if I want it to move, grease. If I want to move it later, anti seize. If I want it to not come lose and not seize, thread lock.

Grease is better than nothing, anti seize is better than grease. If either part is non metallic, consider carbon paste.

I always use carbon paste (even if it's metal on metal). It stops anything seizing and let's you use less torque on the seat clamp which can affect dropper function.

I smear mine in anti-seize: https://www.tredz.co.uk/.Park-Tool-ASC-1-Anti-Seize-Compound_11122.htm

As above, carbon assembly paste is the nuclear option to solve all problems.

Or copperslip 

Or greases made specifically to coat things and stay put

Or generic grease

AND make a note to loosen the bolt and give the post a wiggle once in a while (the ST calendars used to have this). 

I use copperslip or grease for metal to metal and carbon paste if any one of those is carbon...or if a metal post is a fraction undersized and drops in. Then carbon paste that too.

Or Morgan blue aquapaste.

AND make a note to loosen the bolt and give the post a wiggle once in a while (the ST calendars used to have this). 

I wonder if ProBikeGarage can be set to send a reminder?