There are many support materials for music students around now which is great.
Here a few suggestions based on experiences of what has worked well in the past for more advanced pupils.
An excellent resource, Simon Fischer has written articles for the Strad magazine for many years and this book contains literally hundreds of technical exercises, which are invaluable for developing ones playing and supporting work from lessons.
‘The art of practising’ Madeline Bruser
Tips for practising techniques.
‘Improve your sight-reading ‘ Paul Harris
Grade-specific books with a section of exercises and pieces designed to develop often neglected sight-reading skills – these can be an excellent support for developing sight-reading if used on a regular basis.