You are just off the green, quite close to the hole so your first choice is to putt, but there is a big pitchmark on the apron directly on your line just in front of your ball. What can you do about it?
Well the short answer is – not a lot!
Improving your line of play is an example of an action that improves conditions affecting the stroke and is a breach of Rule 8.1 for which you will incur the general penalty. If you make such an improvement and then realise that you shouldn’t have, you can avoid the penalty by restoring the condition as it was using the original object only – you should do this even if you subsequently choose to play a stroke which would have been unaffected by the repair as you would still be liable for the penalty.
Repairs would include such actions as replacing, repositioning, or removing a divot (a divot which is mostly in a divot hole with its roots down is “replaced” and is not a loose impediment even if it is not yet attached or growing).
You are allowed to repair damage on the green (e.g. pitch marks, spike marks, animal hoof prints) whether your ball is on the green or not. However repairing such damage which is not on the green would be improving your line of play in this situation if you are considering playing a putt or low running stroke. Some interpretation is often required for these situations – if you were a similar distance from the hole but had an intervening bunker requiring you to play an aerial stroke then repairing the pitchmark close to your ball would not be improving your line of play. However if you made a repair in your landing zone and not on the putting green that would not be allowed.