I'm soon to visit Crewe and I heard a visit to the maintenance depot is worth a look. Can anyone please advise the best locations for viewing.
Which one?
Off the top of my head there's:
Crewe IEMD (DB)
Crewe Basford Hall (Freightliner)
Crewe Gresty Road (DRS)
Crewe Aviva Traincare (ex LNWR)
Crewe Diesel (now Locomotive Storage Ltd I think)
...then other locations like the 'Holding Sidings' (GBRf locos sometimes) and the Coal Yard (DRS locos sometimes) where you may see things.
Any in particular you've got your sights set on?
None are that easy to see clearly/in their entirety from public areas from what I know - but there's various spots from supermarket car parks, McDonald's, passing trains, hanging off lampposts

etc. where you can see bits of some of the depots.