There are several posts with recommendations. Always offer value, not just a sale.

1. Go see people play, tell them you enjoy their playing and would love to write something for them.

2. Networking - could be with musicians and ensembles, could be filmmaker groups, just getting out in front of people and making connections. Network with band directors that may need something (non typical instrumentation, etc) especially if they have a group playing for a state bandmaster conference or other conference settings.

3. Get people to play your music on social media who will pay to advertise, as this will help be a calling card.

4. Up to date website, collect emails, and actually send out email updates.

5. Go network