I've been interested in photographing bees recently. Rather than buy a macro lens, I spent $32 on a 10mm and 16mm Meike extension tube. Photos are with an A9II + Sigma 35mm f/2, which normally offers a 0.18x magnification. All four are taken as close as the lens will focus. I'm very happy with image quality, especially given that this lens doesn't have a super flat focal plane at its minimum focal distance.
For anyone who tries an extension tube for their first time: you won't be able to focus very far in the distance (beyond about 1 foot in my case). Be ready to get up close and personal.
Extension tubes are pretty fun, but I didn't like the light falloff and got annoyed with the manual focus when trying to photograph things that move a little bit such as living ants or the iris of people's eyeballs. My very first intro to macro was reverse-lens photography where you simply use your lens backwards.
Eventually for macro without a macro lens, I settled on a stack of lens filter step up/step down adapters and one male-to-male filter adapter to reverse-mount my 50mm lens onto any other lens of choice. I also got a body mount to filter adapter so that I could protect the back glass with a UV filter and add a macro ring flash. This whole setup gives you at least a modicum of autofocus, which helps tremendously. Granted, you end up with some extreme fisheye and barreling around the edges of your image, which means you'll lose some fidelity cropping out the garbage.
These extensions tubes have all the electrical contacts for AF to keep working. I'm using an A9 and the AF seems unphased as long as you're under the maximum focal distance.
Hot damn ain't technology great! I couldn't afford the active extension tubes, I was too poor from buying vintage USSR lenses and ridiculous attachments.
If you use the same mm of tubes as you do for your lens then you double the magnification. Meaning if you put 50mm worth of tubes on a 50mm lens you will get 2x as much zoom. This is a great way to get to 1:1 macro scales.
I was really surprised how much difference even the 10mm tube made on a 35mm lens. I am not sure how far I'm going to ultimately take this because I think I want a longer focal length (yay flighty bugs) and the amount of tube needed would be a bit excessive. I had OK luck with my 150-500, which offers a minimum focal distance of around 23" and a magnification of 0.32 at the wide end. Sadly, zooming pushes the minimum focal distance out.