Take this opportunity, while your children are little, to set up good habits with them. It will make things so much easier as the years go by. Try not to be "too tired" to do the mundane but necessary stuff. Read to your child every night, set up routines, take advantage of every "teachable moment", talk to them (I mean really talk to them), make sure they develop good hygiene; bathing, teeth brushing, hair brushing, hand washing, and set boundaries. Yes, you want to pick your battles, but when you pick one, make sure you win it.
If you start now and are consistent, the next several weeks, months, and years will be so much easier, and you will have created a foundation for your child's success.