Batch cooking of versatile basics.
Buy a freezer and good quality plastic storage bowls/ containers.
Don't do 'kids' food' that is separate from what you and DH eat. Everyone eats the same meal together. It's far better for the family in the long run.
It's not necessary to bathe babies and toddlers every night. Once potty training commences, and especially when DCs start wiping themselves, you do need to bathe them nightly.
Buy items like nappies, loo paper, and boxes of tissues in bulk if you can.
Buy packets of white socks, not fancy coloured ones. They're easier to launder.
Pick up as you go along - get disciplined about this.
Go through clothes and toys regularly and get rid of torn, stained, or broken items. Don't allow little 'happy meal' type clutter across your threshold.
Take time every day for you and DH to sit together and chat about your day.
Find a reliable babysitter so you can gonoht together sometimes. Nursery staff sometimes have friends they could recommend.