Any Tips for Sleep Training Five Month Old?

Our five month old baby resists sleep (actively!). He used to be able to fall asleep on his own. We would put him in his bed and turn off the lights when he looked sleepy. Minutes later he would be fast asleep. Now, he cues that he's tired (rubbing eyes, yawning, and later a winey cry) and he won't fall asleep without us putting him to sleep. My husband swaddles him and it takes about 20 minutes for him to fall asleep with a hand on his chest (to keep him from getting out of the swaddle). I hold him which takes 5-15 minutes depending on how tired he is. WIthout these aids, he practically has a party in his room! He talks and laughs and kicks and has a grand time. 15 minutes or so later he starts crying out for us (very overtired by this point) and is so wound up that it is even harder for him to fall asleep. Obviously, we don't let it get to this point anymore as we know babies need their sleep for development and growth. Ideally, we'd like for him to learn to fall asleep on his own, but aren't fans of leaving him to cry. Any tips for helping our very active baby fall asleep on his own?

Suggestion:

Yikes! How frustrating it is to have a baby go from sleeping peacefully, to having a party in their room! lol Has their been any changes at all to his life (teething, growth spurt, new room, any changes to his routine..) I don't think you should have to let your baby "cry it out". Often times when a baby suddenly changes his habits it's because something has changed to his life. At 5 months your little guy is much more aware of his day to day surroundings. growing very quickly and learning new skills. Which is often the cause of shifts in sleep patterns. When your baby is trying to master a new skill his little brain is so overloaded that it becomes difficult to turn it off when it's sleep time. It's not uncommon to have to help your little one go to sleep. The more consistent you are with helping him go to sleep, the sooner he will be back to falling asleep on his own. Try leaving him to settle (cry) on his own for a few min before going in to help him, and increase the time each day by 5 min It sounds like he just needs help winding down after a "hard day" Hope it gets better.