Read the water heater label
Find the tank and read the manufacture date. Past ~12 years, a water heater can leak any day. Look for rust at the base.
Open the electrical panel door
Check the brand, Federal Pacific, Stab-Lok, or Zinsco are worth flagging, and note the service size on the main breaker.
Glance at the pipes and outlets
Grey plastic pipe may be poly-B. Two-prong outlets mean no ground; kitchens and baths should have GFCI test/reset buttons.
Walk the outside
Watch which way the ground slopes, toward the house is a drainage problem, and eyeball the roof for curling shingles or moss.
Bring a fridge magnet
It sticks to galvanized steel but not lead, a two-second test on the service line and supply pipes. And use your ears while you walk: house noises that shouldn't be ignored decodes the bangs, gurgles and hums. Anything you spot on this list is worth running past the insurance pre-check before you remove conditions. New to buying? Start with the first-time home buyer guide.
Most buyers do not skip the inspection because they are careless. They skip it because the market makes them feel they have to. The numbers on that are collected here: what the research says about home inspections in Canada.