Hand covering
Many traditional typing programs will advocate the covering of hands right from the outset, to encourage touch-typing skills to develop more quickly.
However, it is for you to judge whether you feel this will actively help or hinder your learner in the early stages of their TTRS journey.
In the beginning
Quite often, students lack the physical awareness to instinctively "feel" where their fingers are moving when they first learn to press the keys.
This does improve over time.
You may find it helps them to watch their fingers via peripheral vision, as they build connections in the brain and develop their muscle memory.
Being too strict about hand covering, especially for younger students, may lead to frustration.
The way forward
With gentle and persistent encouragement to look at the screen rather than the keyboard, almost all students will eventually raise their gaze.
I can do it with my eyes shut!
Some learners will find it fun to close their eyes and see if they can type a word, line or perhaps an entire module without peeking. It helps them understand the importance of finger positioning. Many people never notice that the two bumps on F and J can help you find the correct starting position by touch alone!
Cover types
If you do want to invest in a keyboard cover, there are many options: rubber skins that fit over the keys themselves, metal or wood covers, DIY constructions using cereal boxes, a small hand towel or a sheet of paper taped at the back of the keyboard with masking tape (though some students dislike the feel of something touching the backs of their hands).
Painting out the letters on the keyboard works as well, but it's a radical choice as it ruins your keyboard for anyone who can’t touch type.
Additional aids
If a student is struggling with a particular reach or combination of letters, try placing a small spot of Blu-tack or putty on the key or keys to make them easier to find by touch.