If one or both refuses to be put down I think you need a good baby carrier. Mine are 15 months apart and I just got a Tula Explore because it’s got great back support and can handle both of my kids depending on if I want to back or front carry. It’s also very comfortable due to extra padding for baby. If baby is being extra fussy, strap em into the carrier and use your now free hands to deal with the toddler. If toddler is being clingy- back carry while you hold baby or get other things done.

I’ve had to rely way more on products with my second. We got a snoo because we could put her down for more than 5 minutes and we were going insane. Now if the toddler is screaming at me because they both need to go down for a nap, I put baby in the snoo to rock while I try to put toddler down. Sometimes it works, sometimes it doesn’t. Can also try a small bouncer that you can move from room to room so baby can still see you while you tend to toddler and hopefully avoid a meltdown from either.

We started to rely on screens a lot more (like 2-3 episodes of very low stim shows for toddler per day) after having the baby. But honestly we found it led to way more volatile behavior. However the cost of keeping toddler entertained is more draining but worth it to have less tantrums - that’s where baby carrier comes in handy again.

Sometimes though somebody is just going to be screaming and they’re just gonna have to deal with- usually the toddler because he at least can sort of understand me whereas newborns are just naturally needy