A lot of rubbish by experienced writer (4,3)
I believe the answer is:
felt tip
'writer' is the definition.
(a felt tip pen is something which writes)
'a lot of rubbish by experienced' is the wordplay.
'a lot of rubbish' becomes 'tip' (I can't justify this - if you can you should believe this answer much more).
'by' is a charade indicator (letters next to each other).
'experienced' becomes 'felt' ('feel' can be a synonym of 'experience').
'tip' after 'felt' is 'FELT-TIP'.
Can you help me to learn more?
(Other definitions for felt tip that I've seen before include "(Pen with) fibre point" , "Variety of pen" , "Type of pen" , "writer" .)