Be dependable. Do what you say you'll do, and do your best. Don't show up late, and always keep your promises. People will be relying on you so you don't want to let them down. Be enthusiastic. Don't moan and groan your way through your volunteer work. If you really don't like what you're doing, find something else. Always have a positive attitude and show others that you're doing this because you WANT to.
Be selfless. Selfless is the opposite of selfish. Don’t think about what you can do to help yourself. Think about what you can do to help others. Be well-trained. Know what you’re doing as a volunteer. If you need some time to learn your job, take that time. If you need training or need someone to show you what you’re supposed to do, speak up. If you’re good at your job, it will be much easier to help others (plus you’ll have a lot more fun).