I start by skipping dinner. (meaning I do eat lunch the first day)

That night won't be a big deal.

Second day you will feel hungry (if it's your first time), and that night may be rough.

Stick with it and you'll wake up feeling fine on day 3. You're now in ketosis. Your body stopped waiting for food and is eating your fat stores.

I consider this the actual start of a fast.

Last time I did it people at work kept accusing me of cheating because I was too energetic. Well, I do have energy.. My body is burning fat!

You'll probably be more low energy than a normal day, but it's not a big deal.

I wouldn't do anything too strenuous, but some people swear by working out during fasts.