If you're trying to get
closer, macro extension rings are often the better option over bellows these days. The variability of bellows was important in the film days with primes, when getting the subject to fill the negative was all-important. A zoom lens and three extension rings will give you the same degree of adjustment, but in all but the super-cheap versions they'll also pass the electrical contacts through. Even when you're shooting manual it's handy to get the right EXIF data on file.
Going the other way, pairing teleconverters with a macro setup will increase the subject distance but you'll take a big hit on exposure. You can go to town and put TCs and extension tubes together on a 200mm telephoto, and you'll be snapping flies from 6ft away. Probably need a tripod for that though