One of the more challenging aspects of learning how to do portraiture using speedlights is that the shadows, and the catchlights, are not visible until AFTER an image has been shot, and then is under review on the LCD...you are in essence "shooting blind" with regard to where the nose shadow falls, where the catchlights are, etc.etc..
In many types of portrait lighting, like Rembrandt lighting, or butterfly lighting, the exact placement of the shadow created by the main light is a critical component of the success or failure. In terms of the so-called views of the face, the main light needs to be moved as the face is turned in relationship to where the lens is at, and again, with speedlights, that means each new face angle (movement of the face), or each new view of the face (shift in the camera position) means that the lighting effect SHIFTS.
The above is important to remember when doing lighting practice with speedlights. You need to look really carefully at the shadows and the highlights and where, exactly, the light or lights hit the subject--in each,specific position of the subject,lights,and the camera. This is something that many lighting books seemingly fail to mention specifically and pointedly,and I think it's one of the most important tips. I think that many experienced lighting practitioners forget some of the most-basic concepts because they have so much experience, and because the majority of them are working with studio flash units with full-time modeling lamps, and they...kind of assume a basis of knowledge that might not always be present in every student.
The more experienced a person is with lighting, the easier it is for them to put the mainlight at just the right height, or the easier it is to estimate where a light needs to be in relation to a particular head angle.
The other C&C suggestion is to put the fill light MUCH closer to the camera position. Fill light is traditionally on-axis, meaning the camera/subject or LENS axis; this is something many YouTube type videos do not convey, and it's common to see horrible cross-lighting setups diagrammed out, with the main and fill lights both raking in from counter-acting,identical angles.