First, allow extra following distance when riding fast on short route segments with many uncertain turns and fully appreciate the stopping characteristics of your brakes and tires. Second, don't carry anything in you back pockets you don't want to fall on like cell phones or car keys. Besides, if you schmuck your cell phone, you won't be able to call an ambulance.
Next, don't try to pack light and skimp on the antibacterial wipes. The wipes don't weigh very much and they come in handy to clean the abraded fleash and boney features on the ankles, calves, knees, palms, wrists, elbows, hips and shoulders. If you keep the wipes accessible, you can clean your wounds while you pedal so you don't have to loose much time. You can also use them in the shredded holes in your shorts and jersey. My wife says I should also carry butterfly bandages to close wide gaping lacerations and gashes but I think that would be too much. I carry a Brave Soldier crash kit but it cost me $12.50 so I'd have to be really messed up to use it.
You know how your palms can get sore and irritable on a long ride? Bruises and abrasions won't improve the personal comfort rating so wearing gloves with abrasion resistant palms is a good safety consideration. Last note to self: a washed triangular bandage would be more versatile than a bandana.