Sleep training that isn’t CIO advice...

My second little one is on the way soon and I’m worried about nap time with another little one to take care of. My oldest never had a good nap routine and bed time was hit and miss. We’ve finally got that sorted out now that she’s a toddler but I’m wanting advice on how to sleep train the new baby from the beginning or at least once they are a few months old to make it easier when I have two kids to take care of. With my first sometimes I spent an hour a day trying to get her down for a nap and I know that’s not realistic with two little ones. Anyone know of any good sleep training that’s preferably not CIO? Thanks!