To make it easier to get infants into their carseats, attach a toy (the kind that tethers to a stroller) to each car seat strap. The toys act as weights when hanging over the sides of the seat — holding the straps open and out of the way.
Bonus: two toys ready to be played with during the car ride!
Safety note: If you're going to keep the toys attached to the seat during the ride, I'd stick to soft toys only, and keep the tether very short. Instead of the little plastic chain links sometimes used for this purpose, use a fabric tether such as the Secure-A-Toy or a simple Velcro strap.
Also, be sure the toys IN NO WAY interfere with the workings of the straps.
(Am I missing other concerns here? It's a great hack, but something about attaching things to car seats makes me shifty. Reality checks welcome.)
This would also work beautifully for a stroller or high chair with a 5-point harness.
More: Car seat hacks