The most common and most likely answer to this crossword clue is the 4 plus 2 plus 5 letter word RULE OF THUMB
I've seen this crossword clue in Independent
R
U
L
E
O
F
T
H
U
M
B
More clues leading to the result RULE OF THUMB
- Governance by one on hand to give guidance
- Practical guide for digital supremacy?
- You finally sign paper protected by one of 32 points giving rough guidance
- Guideline when Tom’s in charge?
- The hitch-hiker’s guide?
- Practical method shown by digital supremacy?
- Rough guidance for digital governance?
- Practical instruction for securing a lift?
- Guideline set by Tom when in charge?
Buddy explains!

The straight part
We know that "rough guidance" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case rough guidance = rule of thumb.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.