Find some way to stay accountable. This is helpful for because I don't like disappointing people. So, if I have someone to keep me accountable I'm more motivated to practice because I want to give them a good report. Posting a video everyday during my 100 Days of Practice Challenge also kept me accountable.
2. Set Goals
I like to set goals with specific time frames in which to meet those goals. For example, when I started the 100 Days of Practice Challenge, I set a goal for where I wanted my sound and technique to be by day 50 and then where I wanted my musicality to be by day 100. Make your goals and time frames reasonable but at the same time push and challenge yourself.
Look for inspiration from different sources. This could be books, YouTube videos, or whatever you find to inspire you. My dad is one of my biggest supporters and motivators. When I'm feeling less-than-inspired or unmotivated I call him and all I have to say is "I need some motivation". He knows exactly what I need to hear and begins reminding me why I chose music and to pursue my dreams. As one of my biggest supporters, he inspires me to keep working hard for my goals and dreams.
Staying accountable, setting goals, and finding inspiration are three things that can help you stay motivated in your practice time. There are many ways in which you can help motivate yourself but these are the three that have specifically helped me and I hope they can serve you well also. Feel free to comment below with what motivates you to keep practicing and pursuing your dreams!