My fav method is the thwack, plus knit pick at 530am.
This is severe damage and shows an active spot being nibbled.
You can locate what I call tracers which is top level cell damage from small baby caterpillars. This helps identify what tier they are at.
The moth mamma lays eggs randomly soread throughout the plant, caterpillars seem to stay near same tier for a long while.
Some are very very small.
They are different colors at different stages of life. There are 5 in this pic, can you find them?
Small black dots indicate an active caterpillar that has eaten recently and is on that tier of leaf.
They prefer the flowers.
Check for initial leaf damage, then go to flower on that tier. Check up and down.
Check underneath leaves and close to the actual bud.
The hardest thing is their natural camoflauge.
I check for then daily in the early am.
This is when they are just getting up and start moving to feed.
Another method I have started using is the thwacking.
I thwack an entire branch, then jiggle the whole plant like I am shaking almonds. Sometimes they fly off large in numbers and wriggle around on the ground.
Good luck, I have one plant being hit hard now and pick off at least 5 a day for past week.
Mine are also inside my veggie garden, and I have hundreds of bait plants to choose from. Ugh.