How Best to Reinforce Previous Lessons

I find that as proceed through lessons, I feel like I start to forget vocabulary I learned in previous lessons.  Is there a recommended systematic approach for continuously reinforcing the items learned from previous lessons?  Thank you!

Ailike, I have been working seriously on the Mandarin for the last four years and find RC is excellent for reinforcing previously studied content.  However, it requires that I continuously reiterate early lessons.  RC acts as my very patient tutor and repeats the lessons while my brain builds and strengthens the neural networks.  I recommend using RC to expose yourself to the language on a daily basis and at different times of the day.  Good luck.

Thank you Nóng Fū!  I barely find time to advance in the lessons so going back can sometimes be hard.
When you go back, do you redo the entire lesson or just the exercises?

Xièxie!

Eric

I always pick and choose what is most interesting to me.  Oftentimes, I multitask with a YouTube video or Netflix while working the RC. 
 

What is the RC?
I've been having some of the same problems as Ailike, but I don't know what the RC is. 
So what is it?

谢谢！

Rocket Chinese!

Oh! 
I don't see how I didn't figure that out.