Online tax software means filing your return is much simpler than the old pen and paper days, but many net filers still miss important deductions that can best maximize their return.

Cleo Hamel of H&R Block says large medical expenses and tuition receipts are often missed.

"Now we have the child fitness credit, moving expenses. Those ones tend to be the higher missed dollars," he said.

Almost three-quarters of Canadians don't realize they can claim their private health and dental premiums they pay through payroll deduction, Hamel says, including not claiming the remaining portion you're on the hook for after your insurance payouts.

"You're submitting your receipts for glasses and braces, the chiropractors and maybe you only have to pay 10 to 50 per cent. Well, the portion you are left paying still counts as a medical expense," she said.

A family should lump all their medical expenses together and have the lowest income spouse claim them. The same applies to child care expenses. The person who makes more money will get less of a credit because of their higher income.

Another common mistake is not filing your taxes at all if you didn't make much money.

"When we talk about families for instance and they have children and they are currently receiving the universal child care benefit or the child tax credit if you don't file every year those payments will actually stop," Hamel said.

The same applies for seniors who qualify for special low income benefits and people aged 19 or older who are eligible for quarterly HST cheques.

You should also watch out for any changes with the Canadian Revenue Agency by looking at their "what's new" section in the first few pages of its annual guide.

"Go through that section with a highlighter or a pen and read through all the things that are new and figure out which one of these do I need to be familiar with," Hamel said.

If doing your own taxes seems too daunting it's sometimes a good idea to talk to a tax professional. They can often find deductions that will more than make up their fee.

With a report from CTV British Columbia's Shannon Paterson