I was hoping someone can share how they managed to do the drowsy but awake for a spirited baby when I don't seem to have that state.She goes from happy to cranky
my DD1 was like this and never really (still doesn't) get to the drowsy but awake stage. The cranky bit didn't always mean she was tired though - I think often she was just getting bored. Because of these things, it was quite hard to gauge her A time! The best way to judge was from experience and how easily she would nod off for a nap.
Do you have a winddown routine? I found mine couldn't be too long but introducing one and keeping it consistent each time really helped her learn that sleep time was coming. I would swaddle her (or, when she got older, put her in a sleeping bag), walk around a little with her singing/humming a lullaby, and then lie her down in her moses basket and shh-pat until she fell asleep. If she got really upset I'd pick her up and carry her around until she got calm again (she needed the motion, just sitting and holding her wouldn't work), then put her back down. She would never fall asleep on me unless she was in a carrier.
I found it easier to put her down for her first nap of the day and the others were harder. So I started with just the first nap in the moses basket, and the others were in the pram or a carrier (I did a lot of walks with her!). Then as she got older and things we going ok with the first nap, I'd try for later naps too.
Not sure if that helps you, but that's what I ended up doing!