I tell my kids do the little easy assignments immediately- the little points you get give a buffer if you screw up on something big.
And only do extra credit if the benefit is equal to or greater than the effort required.
I want them to get good grades in the laziest way possible- prepare them for the future when their asked to be on some committee or do some task that wastes their time and provides them no benefit.
Turn in anything even it’s crap is worth adding.