not beginner-friendly: which techniques are not suitable for beginners?

Dear users, dear authors,
which techniques are not suitable for beginners? What would you strongly advise beginners with basic skills against?

I would advise against lace patterns.
Especially if there are several that differ in the number of rows and stitches.

Absolutely. And I also find post double crochet quite fiddly.

Not all beginners are the same. 😊
Some can quickly try more difficult patterns, while others still need a bit more practice. 

I’d recommend trying out patterns on smaller pieces first. 

For example, as dishcloths or washcloths. That’s also a good way to test a lace pattern.

What I find challenging for beginners, for example, is Fair Isle knitting.

I think double-face isn’t exactly easy.