I use this loupe:
BelOMO 15x Triplet Loupe Magnifier. 9mm (.35"). It's a bit pricy at $40, but it has excellent optics.
@GNick55 recommended it.
Loupes are good for a quick look just to check the progress. They don't work well for taking pictures, though.
There are plenty of inexpensive digital microscopes on Amazon. I have one that cost me about $30. The one I have has a stupid method for connecting to the phone. Another problem with those is they're hard to hold steady and the plants don't like to stay still, either. I tried turning off the fans, but the plants still wobble. When looking for critters, I cut off a leaf and use a desk.
To photograph buds while still on the plant, I figured out a way to mount a digital microscope to a camera tripod. It can be a challenge to get it close enough to the plant. The plant still wobbles, though, so next time I might try to devise a way to keep the stem still.
Someday I might pay bigger bucks for a digital microscope. There are some nice ones for $150 to $200.
Here's a picture of some Acapulco Gold bud I took with my $30 digital microscope from a tripod.