The following three have been most rewarding to me. Even if they are not spawning, the warmer flowing into the lake attracts all forms of aquatic life - a buffet of insects, crustaceans, and baitfish. Activity seems to subside with the onset of daylight. An exception is the mouths of large rivers, where lakers might feed into the day. Look for a boulder-strewn point that has a series of dropoffs to deeper water, rather than a gently sloping point without bottom cover.
Rocky points provide food and cover for baitfish, which in turn attract lakers.
During low-light periods, fish right up on the point. Concentrate on deeper sections or edges during the day. Many anglers ignore them, yet some of my best spring catches have come from the massive sand beaches at Wasaga Beach on Georgian Bay and Sandbanks Provincial Park on Lake Ontario. Sand soaks up the sun's rays, quickly heating the water. I recall the first time I fished for spring lake trout.