I've always been religious about avoiding excessive sunlight exposure but lately I've been wanting to get a tan... I just think it makes a person so much sexier. The problem is, having been so uptight for so many years about avoiding the sun, I have trouble letting the sunrays hit my skin without feeling scared of sun damage.
Sun damage is very real thing, UVA rays are present all year round, penetrate clouds and glass and deep into skin, down to reticular dermal layer or so. Best thing - it's cumulative, so even if you get 20 min sun expose it still adds up to total damage. Leads or horrible, horrible degeneration called aging and sows seeds for cancers.
I think the mentality that tan is beautiful/sexy is a very Western one. I've never thought of tan skin as attractive, it seems ugly to me. Deep beach tan is kinda repulsive.

And that was when I was a little kid before I knew about the UV damage and cancers.
I've only done the tanning bed thing twice in my life and while I liked the tan, I was so nervous in the days afterwards, scared that I'd permanently damaged my skin, I'm iffy about going down that route again. Are tanning beds more safe than tanning under natural sunlight?
Tanning beds are worse than natural sun. They have mostly UVA rays, those who make pigment cells turn skin dark. They are also 5-50 times more intense than real sun. Most tanning beds don't use UVB (the ones that produce vit D) rays because they create burns. UVB lamps are used mostly in medical settings to correct some conditions, but that's a different kind altogether.
Fun fact, while UVB rays produce vit D in skin, UVA rays destroy it. It's natural safeguard from prehistoric times to keep humans from overdosing vit D. If one uses tanning beds then UVA rays actually reduce vit D levels in skin and other vitamins get depleted at well, vit A and C for starters.
How do models get tanned for photoshoots and the runway? I would think since their careers are based so much on their looks they won't want to take any chances with doing anything that could accelerate the aging process.
They are young, in their early 20s or so. Even if they bake in sun or tanning bed the effects are not that visible. Some older models (over 25

) do have pretty damaged skin, especially male models.

Could also be that they use self-tanners or bronzers when models need to look tan.
Does spray tanning work? What's the best way to create the most natural looking tan without compromising your skin's health?
Self-tanners and spray tan does work, it works by applying a chemical called dihydroxyacetone (DHA) among a couple others and skin's proteins undergo enzymatic oxidation reaction which creates the color. Since it's oxidative reaction it creates free radical molecules which add to skin's oxidative stresses.
2007 research by K. Jung showed that skin treated with DHA is vulnerable to UV rays 24 hours after self-tanner use. An increase of 180% in free radicals was discovered on DHA treated skin exposed to UV light.
What that means is that 24h after self-tanners sun should be avoided.
http://www.gematria-test-lab.de/pdf/SelftannerSoeFW2008.pdf