Giving advice

 

I would advise you to DO...

Personally, I think your best course would be to DO...

(slightly formal)

 

It might be a good idea if you DID... (tentative)

Your best bet would be to DO...

I suggest you DO...

Why don't/can't you DO... (direct)

I think you should DO...

(If I were you) I'd DO... (direct, informal)