Krishna distills the three gunas into their core outputs. From sattva: knowledge. From rajas: greed. From tamas: carelessness, delusion, and deeper ignorance.
This is a mirror you can hold up to your own mind at any moment. What is the predominant flavor of your thoughts right now? If clarity and understanding feel close at hand, sattva is leading. If the mind is calculating, wanting, strategizing how to get more of something, rajas is in the driver's seat. If a heavy fog has settled and basic tasks feel like climbing a mountain, tamas has moved in.
For anyone who wants to grow in knowledge and understanding, the prescription is implied: strengthen sattva. Sattvic food, good company, study, and meditation all nourish it. The guna you feed is the guna that grows.