There's a lot of information on the internets about proper trail etiquette, but we think that Boulder Mountain Bike Alliance has nailed it with the following advice so we are not going to reinvent the wheel. Check out their website to get more information. 

Trail Etiquette 101

• Smile. Greet. Nod. Every user on the trail is a fellow nature lover. Be friendly and expect to see other folks around every corner
• Don’t block the trail. When taking a break, move to the side of the trail. Yield right of way to uphill riders.
• Stay on the trail. Don’t go off trail (even to pass), create new trails, or cut switchbacks. Narrow trails mean less environmental impact and happier critters.
• Don’t use wet trails. If mud is sticking to your tires, it is too sloppy to ride.  Avoid freeze-thaw sections at all costs, this is when a wet trail deep freezes on cold clear nights.  The sun then turns the trail to peanut butter.  If you want to ride more throughout the seasons, please learn how different trails handle weather.  Yes recent temperatures, and precipitation affect trail conditions, but trail aspect (North-South) and whether it has tree coverage is also critical.  Lastly, soil type plays a huge factor if you can ride when it is wet.  When in doubt, ride lower Syncline.  Remember, there are snow sports if the conditions are bad on lower Syncline .... or an indoor trainer.
• Right of Way. In general, uphill traffic has the right of way. When riding motto trails in Post Canyon, give mottos the right of way. Remember: They can’t hear you (because…mottos), but you can hear them. 
• Ebikes. If you’re riding an ebike, please be respectful when passing on the climbs. On Eldorado in particular, look out for young kids who descend on this trail and don’t expect to encounter fast uphill traffic.

Most importantly, have fun out there!