a little help from the shrewd ones on here

any advice for betting. my current method of essentially going through the card is hugely frustrating and costly. what do the shrewd ones do on here. do you lump in on shorties?? back long shots?? watch races looking for the unlucky ones and back them next time?? follow trainers?? there seems to be a few on this forum who actually get plenty of winners/ profitable outcomes each day. any help will do!! cheers