Officers say every year they receive complaints about callers who post flyers offering services such as household repairs or garden clearance.
They warn that these traders often use misleading or intimidating practices to obtain large amounts of money.
Vulnerable consumers, particularly the elderly, are most often targeted.
The guidance issued by Moray trading standards advises householders to never agree to employ a trader who cold calls at their home.
It warned: "Doorstep sellers are often trained in pressure sales techniques and they can be very persuasive. The best protection course of action is to say, 'No thank you' and close the door.
"Common complaints include poor quality of work, quoting a low initial price which goes up significantly because of 'extra work' needed, or exaggerating the risks that consumers face if they do not get repairs carried out.
"Householders who think that work is needed to their property should get quotes from two or three traders or ask someone trustworthy for a recommendation."
The organisation also appealed to the public to report any suspected rogue traders.
The guidance said: "Many instances of doorstep crime remain unreported because victims are embarrassed, they don't know who to report it to, or they do not even realise they have been the victim of a crime."
Moray Council's trading standards team has issued a warning to householders to be on the alert for unscrupulous doorstep traders.