Staightforward procedures involving one in poor health (5,7)
I believe the answer is:
plain sailing
'staightforward' is the definition.
I can't tell whether this definition defines the answer.
'procedures involving one in poor health' is the wordplay.
'procedures' becomes 'plans' (I can't explain this - if you can you should believe this answer much more).
'involving' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'in poor health' becomes 'ailing' (I've seen this before).
'plans' placed around 'i' is 'plains'.
'plains'+'ailing'='PLAIN SAILING'
Can you help me to learn more?
(Other definitions for plain sailing that I've seen before include "easy job" , "No problem (for yachtsman?)" , "A breeze" , "effortless progress" , "Easy and unobstructed progress" .)