We have two things that help - ensuite and a lock on the inside of the bedroom door. Makes it easy to wake up, sense that all the kids are asleep, pop to the loo, lock the door and back to bed for a quickie.
Another thing we have done is to book baby-sitter etc. for a grown-up night out at a restaurant. But, what no-one else knows is that we also book a room in an adjoining motel - not to stay the night but... everyone thinks we're just having a long drawn out meal and grown up chat!
I think you need to be willing to accept both lots of quickies and also to have pre-planned love-making as well.
HTH
My wife works shifts and at the moment she's on nights, so tend to fit it in when she comes in from work or during the daytime when she wakes up, preferably before picking kids up from school! It's a big part of our relationship so we tend to make time for each other :)
Take those moments when all is quiet and utilise them! For us, when the kids have fallen asleep and one of us is finishing the washing up before we veg out on the sofa...or when we come up to bed,before we get too comfy and give in to sleep.even if they are quickies. Not every night, but its about keeping the intimacy in and around the busy day to day stuff.we also make sure we were physically demonstrative to each other (hugs,touch ect) on days where we dont so that we keep the connection.we are also planning one night break for our anniversary and we are so looking forward to that!!