This lesson is the other half of the opposite-hand rule. Right Shift capitalises left-hand letters: Q W E R T A S D F G Z X C V B.
The mechanics
The right little finger reaches down-right to Shift from its home on ;, holds it, and the left hand types the letter as normal. Shift first, then the letter, then release both.
Why this half is harder
Most people find right Shift noticeably more awkward than left, for two reasons.
It gets less practice. English capitalises far more words beginning with left-hand letters than you might expect — The, A, We, QR, Data — but the sentence-initial capital that people type most often is T, a left-hand letter, requiring right Shift. So the harder key is also the more frequently needed one, and self-taught typists almost universally cheat it with the left hand.
It is also a longer reach on many keyboards. Right Shift is usually a wide key, but the right little finger is already responsible for ;, ', P, Enter and Backspace. Adding Shift to that workload is what makes the finger tire.
The habit to break
If you have typed for years without formal training, you almost certainly use left Shift for everything. It will feel wrong to stop, and your speed will drop for a week or two while the new pattern establishes itself.
Push through it anyway. One-handed Shift is a hard ceiling on your speed, and the longer you leave it, the more repetitions you have to overwrite.
Practice notes
Drill sentence beginnings rather than isolated letters — The, That, Ask, Every, Would. Each one puts right Shift exactly where it appears in real writing, immediately followed by lowercase letters on the same hand, which is the transition that trips people up.