Well why are you coming to Canada? Where will you be staying? What attractions/landmarks will you see? How will you get to those places? How much will it cost you to go there and spending? You need a detailed plan of what you're trying to do. Simply saying "I'm just there to visit my family" is very generic.
Also be warned that every time you are refused a visitor visa, each future attempt will be more difficult, so you're just digging yourself a deeper hole each time unless you can directly address their concerns.