Smallest cutting I can take from seedling to clone?

I have some seedlings that have been growing from the baby leaves for 2 weeks, most are on the 4th set of fan leafs.

Can I take 1 cut from some of the bigger ones and clone?

What is the smallest cut you have successfully cloned?

Should I aim to make the cut at a certain part on the plant?

Wait until the 5th node and then top it. Save all your tops to clone.

the bigger i can make clones, the better luck i have with them.
as far as where to take them, i like to take clones from low on the plant, hardly ever get a top to root.
if you want the branch to keep growing, make sure you leave at least one node with a leaf or two, and it'll start growing again after you cut it.
you can root tops, i won't say it won't work, i just have trouble with them.

I've taken and rooted 2 to 3 inch clones. But the bigger the better