Rules to follow putting up sample of precious wallpaper (4)
I believe the answer is:
laws
'rules' is the definition.
(law is a kind of rule)
'up sample of precious wallpaper' is the wordplay.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'sample of' says the answer is hidden in the clue (I've seen this in other clues).
'swal' is hidden within 'precious wallpaper'.
'swal' in reverse letter order is 'LAWS'.
'to follow putting' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for laws that I've seen before include "Rules imposed by authority" , "code" , "Codes of action" , "legislation" , "Rules, statutes" .)