I have a large seatbag that I carry my spare tube or two ( depending on ride length) tools, co2 x 2 ,co2 pump, small patch kit, small first aid kit, money and keys.
I have a bento box which I use for food and phone (and maps if I need them ).
I wear my ID around my neck and anything else goes in my jersey pockets.
I also have a pump on my frame.
My husband often laughs at me for the amount of gear I take but it makes me feel confident that I can cope with most situations.
I was glad for my small first aid package when I was stung by a bee on my first organized ride - wiped down the sting with stingoes and away went the pain and so did I to finish the ride happy.
The most effective way to do it, is to do it.
Amelia Earhart
2005 Trek 5000 road/Avocet 02 40W
2006 Colnago C50 road/SSM Atola
2005 SC Juliana SL mtb/WTB Laser V