I wouldn’t worry so much about having body fat (if that is what you were asking). However, I have some temporarily ‘slimming’ tricks I sometimes employ.
I monitor what I eat the night before or the day of. I avoid stuff that will make me bloated, like lots of salt, bread, heavy meals, etc. I’m very slight of frame, and that sort of thing is very noticeable on me, not to mention it can be personally distracting and sometimes uncomfortable. I always try to go to the bathroom before a gig.

It doesn’t so much matter how you look, but it’s simply how well you hold still, and take direction, if it is even given.

Another tip, have a good mix of sitting or standing poses in your ‘bank’. You can also include a reclining pose or two, but whether or not you use that kind of pose is dependent on the class set up. For example, if all the students are standing at easels and you aren’t on an elevated surface, laying down for a pose might be discouraged. Also, always try to make sure that every artist gets one good view of a pose. For example, if your are in a walking pose, those who are looking at you from the side get the better view of the pose. Be aware of at what angles a pose looks good in, and try to turn your body so everyone can get at least one good drawing.

Oh yeah! when you assume a standing pose, try not to lock your knees. Sometimes, for a reason I’m somewhat unsure of, standing with your knees locked for a period of time can cause you to faint. I’ve almost done it myself, so always make sure your legs are a little relaxed.

I’m not so sure about a specific website that could help… I did find this http://www.modelreg.co.uk/ It looks rather bare-bones, but it seems the majority of the info is up to date.

However if you’re still having trouble finding work it might be time to dig a little deeper. I mentioned this above, but it’s such a jumbled mess I’ll try to make it a little clearer.

Make a short list of places and phone numbers that do, or may, have figure drawing classes (colleges/universities, museums, artsy places, etc). Also, prepare a short little introduction for yourself, and write it down to read off of.

For example if you have a number for a school, you would call and ask to speak to someone in the Fine Arts department, or if you have that department’s number already, ask to speak to the one who organizes and schedules models for classes.

“Hello, my name is __, and I am looking for work as an art model. Can you tell me how to apply?”

From there they may ask you to describe yourself, so have a few short descriptive phrases ready. If you have access to costumes, which obviously is not a necessity, be sure to mention that also.

If you don’t get a job right away, wait a couple weeks and call back. If it is the beginning of a semester or term, it is best to call at least 3 times in the first 6 weeks, although I suppose that’s a good rule of thumb for anytime. Always remember to use your name, and try to speak to the same person you talked to before.

I’m not sure if this was the kind of information you’re looking for, but I hope this helps to clarify for you and anyone else looking for work.

Aww, thank you for your kind words, Ewan. I read your How I Did It story… How exciting! I’m so glad modeling has helped you so much.

People are always so impressed with models “You are so brave!” but I just tell them “Some people, when you see them, are in uniform. When I work, I really am in uniform.”

Hi Aaron. I’m always glad to help. :)

My mentor no longer trains models, so I feel it’s kinda my duty to share the knowledge.