National Geographic has an excellent explainer on how to improve your macro photography skills. What it boils down to is don't be afraid to experiment, play with angles and aperture, come prepared for the unexpected, and be patient.
Image credit: John Kimbler
In macro photography, your background will naturally be thrown out of focus. This is something you should have fun with.
Image credit: Peter Martin
Know your lighting; You can try to shoot on bright sunny days or even overcast days so as to avoid unwanted shadows.
Image credit: Terry Bridges
When the perfect shot literally walks under your nose, have your camera ready and make sure your settings are correct. Be quick or you'll lose it!
Image credit: Ankit Mavchi
For more tips, head on over to NatGeo.