Tenant was wont to muddle advice on economy (5,3,4,3)

I believe the answer is:

waste not want not

'advice on economy' is the definition.
(means of being economical or thrifty)

'tenant was wont to muddle' is the wordplay.
'muddle' is an anagram indicator.
'tenant'+'was'+'wont'+'to'='tenantwaswontto'
'tenantwaswontto' with letters rearranged gives 'WASTE NOT WANT NOT'.

I've seen this clue in The Guardian.

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