Bigger, rounded items of the aircraft create a flow field that slows down the rate of ice accretion, compared to smaller, thinner items.
So look for ice to begin accreting first on things like windshield wipers, OAT probes, and wire strike protection blades.
Those kinds of things on the aircraft are what you pick out to look at.
You will see ice accreting on these sorts of shapes and projections first.
You should be aware of likely icing conditions during preflight planning, so as to stay out of them.
But there is an old saying, "Ice is where you find it," it's hard to predict, many variables.
So no matter what the forecasts or rather lack of icing forecasts, I always tell people, when you punch into cloud, take a look right away at your OAT gauge and scan it regularly.
If the temps are right in cloud for icing, basically +2C to -15C or thereabouts, take some action to get out of that environment.
Know the temperatures aloft from preflight planning, climbing won't always get you into the colder air and descending won't always get you into the warmer.
On that note, a temperature inversion mixed with cloud is a likely recipe for freezing rain type conditions, DON'T GO THERE.