Tip 109: The Farmers' Market Pumpkin Emergency

Low-milage vegetables sing a siren song to the inner-urban 30-plus hipster - much like the bottom shelf of the boxed wine section cajoled their early-20s selves.
Arriving by car is a shameful act of bourgeosieism, even if it is a Subaru with cyclocross stickers / high-credibility carbon fibre product perched on it. Go by two wheels.
Remember this, however: root vegetables are peril.  Load a bunch of local carrots, spuds and a biodynamic pumpkin into your pannier, and when you cross the Elizabeth St tram tracks you're gonna hear a noise that means you've popped a screw out of your rear rack and snapped a swag of spokes.

BONUS TIP: Tweet the following: "Attack of the killer potatoes! locavorism ruined my bike!  :| "
Then hit the net to buy replacement components made in Taiwan, branded in New York, packaged in plastic and shipped by air. You don't need to tweet that.

Tip 108: Learn something

Ignorance is bliss. The flipside is that learning can be quite painful, like using your finger as a front derailleur.
You can learn something new from bike shop guy, like how there's this new kind of bottom bracket that makes everything prior seem to have the weight of lead and strength of paper mâché.
You can learn something new from Sheldon Brown, like how proper chain maintenance is as simple and accessible as ascending K2. ;)
You can learn something from someone you meet on your ride, like the many benefits of gloves.
Lastly, you can learn from a process of trial and error, but the terminology is quite misleading.  It should be trials and errors. No-one learns properly the first time.

BONUS TIP: Lessons learned this last way will send you on the long ride to being a better cyclist, but not until you've stopped in for a hot steaming cup of my-bike-my-gear-and-my-technique-all-suck at Cafe Doubt & Despondency.