Longevity of an easy routine

I struggle with consistency in my routine. I decide I'll start retinol slowly, then laziness don't do it... I wear sunscreen most days, and on the days I do I always double cleanse, but if I don't put sunscreen or makeup on I don't bother. My skin is pretty much fine though, apart from a pimple a month where I touch my face a lot! Wondering if vitamin c, or another active ingredient would suit me.