I am usually very good at keeping up my practice schedule and I wanted to share some tips to help everyone feel more motivated to practice.
If you practice you get better. I continually tell myself this. Think of the goals you have, whether you aspire to be a professional musician, head off to a music college or gain a seat in a band. The only way you will achieve any of these is by practicing. I myself dream of going to a music conservatoire and I know that I need to practice hard to achieve this. I find it helpful to make a list of things I hope to achieve by the end of each week, this means I know exactly what I have to practice and gives me something to work towards every time I sit down to practice. Give this a go, we all know how enjoyable it is to be able to cross things off a list!
Watch videos of people playing on Youtube. Every time I am working on a new piece I like to find several different performances of it. This not only helps me to get an idea of how to play it but also makes me feel motivated to practice the piece.
If you have time, break your practice sessions into more manageable 'chunks'. I typically have four individual sessions each day. This is important for trumpet players to give your lips time to rest but also useful for other musicians in order to keep practice sessions more interesting. Work on something different each time and don't keep them longer than 40 minutes. This will also help you to keep more focussed and achieve more.
Let me know how you keep motivated to practice.