Support, support, support, support. Seek out support groups you can go to (go now while pregnant to get to know people an familiarise yourself with breastfeeding) and seek out any organisations who can do home visits etc. Educate yourself on what is normal for a breastfed baby (books supported by LLL-La Leche League - will be better than a random parenting book that is trying to make money by selling a "way" to parent, or there is the LLL website). Educate anyone around you whose support you need, who might accidentally undermine your decision to breastfeed.
There's no one "tip" that makes everyone's life easier because every mum and babe are different. Pain is very very common while you learn but it can be a sign that somethings not quite right, so don't try to power through thinking that's just "how breastfeeding is". It's so hard to succeed and be happy doing something that causes you pain, so seek help with pain as early as possible.
Get help with everything else you need doing - older children, meals, housework. You need time to bond and learn with the new baby, everything else can wait. Older children do need you but they can cope with all the practical things being done by Dad/Grandma/Auntie/Friend so all you need do is snuggle with them and listen to them and show them the baby. Think what a brilliant education that is for boys and girls that new mums need nurture, rest, support and time. And remember this WONT BE FOREVER.
