What to bring to an action

Wear Layers:

Pants with deep pockets
Long pants even in hot climates.
A tee shirt and long sleeved shirt for sun protection.
Sweaters, sweatshirts or jackets as needed.
Appropriate colors, capes, patches, costumes, scarves, etc.
A sun hat!!!
Raingear may be necessary.
Have a second outfit for a second day of action, if tear gas is a possiblity.
Sturdy walking shoes (waterproof boots if rain is likely, if not, sneakers may help you move faster.)
Sunscreen‹water based, not oil-based as tear gas and pepper spray bond to oil.
A light daypack or waist pack for food, change of clothes, etc.
A money belt/waist belt is handy for ID, some cash, etc.
Water! A water bottle, waistbelt, or other system for carrying water is useful.
A bandana.
Food - trail mix, protein bars, compact stuff to munch on during the day.

Some nice things to have:

A drum, rattle, finger cymbals, etc.
Sidewalk chalk.
A cell phone. (Don't forget your charger.)
A watch.
Rescue remedy.
Toilet paper.
Patches, banners, signs, flags, etc. Think of ways to write your message on what you wear as well as what you carry.
Extra glasses or contacts.
Fingernail clippers (will cut through plastic handcuffs.)
Wear two pairs of underwear if you are at risk of arrest. (if you can keep them both in jail you¹ll have one to wear and one to wash.)
Extra tampons or pads.

For gas protection:

A bandanna, soaked in vinegar or lemon juice, kept in a ziplock baggie to conserve moisture.
And shatterproof goggles. Or a paint mask or filter. Or a gas mask.
Water bottles with squirt tops for washing eyes.
Check with the medics for other supplies (solutions of half water, half Maalox or other liquid antacid are recommended for tear gas) (but NOT mint-flavored!)

If you wear glasses: Either find goggles to fit over or put them on a string so you can take them off and put goggles on instead.

If you wear contact lenses: Contacts should be removed if you are hit with tear gas or pepper spray. I save my disposables when they can still take an extra day's wear, wear them into action so I can just pop them out and drop them quickly if necessary. I carry my glasses or a spare pair of lenses. If yours are not disposable, keep a case with you and be prepared to remove them quickly.

What to bring to the overall mobilization:

At least two street outfits for multiple days of action, in case one gets tear-gassed.
One nicer outfit for doing media interviews if needed.
Layers of clothes for a variety of temperatures.
Bedding if needed.
Big markers.
Art supplies.
Cloth for banners, etc. (or make ahead and bring.)
Your own cup, plate silverware for those Food Not Bombs meals.
Originals for flyers, informational materials, etc. that you can get copied as needed.