Quick disclaimer, all drawings are done by me, while I try to remain as accurate as possible, I am only a student. There are natural human variations and differences between textbooks. That being said, I hope my illustrations can be of some help.
The Suboccipital Triangle is pretty much what it sounds like, a triangular region formed by muscles below the occipital bone.
Lots of long names here for such small muscles, but there is a method to the madness. The 2 Obliquus muscles attach at an angle (Oblique = slant). Superior and Inferior just tell you location, i.e. Obliquus Capitis Superior is above Obliquus Capitis Inferior. The 2 Rectus muscles attach straight up and down (Rectus = straight). The Rectus Capitis Posterior Minor can be broken down into: a straight small muscle located at the back of the skull. Rectus Capitis Posterior Major brakes down into: a straight larger muscle located at the back of the skull. Thank goodness for latin.
Netter, F. H. (2019). Atlas of human anatomy (7th ed.). Philadelphia, PA: Elsevier.
Moore, K. L., Agur, A. M., & Dalley, A. F. (2015). Essential clinical anatomy(5th ed.). Philadelphia: Lippincott Williams & Wilkins.