Arizona State University
Arizona State University: Thoughts on Practicing
Many great tips and strategies are provided here to help with practicing. Although written for oboe players, the advice here can apply to any instrumentalist.
TED Talks
Ted: Ted Ed: Music as a Language
Can learning to make music be as unstructured as learning to speak as a small child? Bassist Victor Wooton makes that argument in this TED Ed talk. Free registration is required to receive full access to the the complete lessons.
OpenStax
Open Stax: Catherine Schmidt Jones: A Guide to Great Home Music Practice
Offering good tips on practicing, this site goes into some detail on how to best use your practice time.
OpenStax
Open Stax: Catherine Schmidt Jones: An Example Intermediate Horn Home Practice
If you are a French horn player, you may get a good idea of how to practice from this resource. It provides general ideas of what your practice routine should include.
Other
Influence vs. Imitation
An interesting article debating the issue of whether influence and imitation can cause a young musician to lose their own creativity. The column is well written and provides some good insight.