CREDIT: STAGSHOP.COM

With so many options, it can be hard to decide what lingerie and sexy costumes you should buy to impress your partner. Even if you're a seasoned lingerie shopper, it can be difficult to pick out that perfect little something sexy.

This guide will help you get over your fears and step confidently into the world of leather and lace.

Know what you're getting into
Former lingerie saleswoman Jess Snow said, "It's always easier if you can go into a store knowing what you want. It makes the job of helping you a whole lot easier."

Finding the right size
Before heading off to the closest lingerie shop, it's important to know what size you're looking for — especially if you're buying a sexy gift for someone else.

If you don't know your size, you could always ask a salesperson for a measurement. If you're shopping for someone else, try to avoid outright asking your partner their size, as she might be uncomfortable sharing. Instead, try sneaking a peek at some of the tags on bras and other things she already owns.

"There have been so many guys who try to guess what size their girlfriend is, and then, when they give her something that is nowhere close to her actual size, she freaks out. I've had men come back the next day to return something and tell me they got an earful for not knowing the right size," Snow warned. Don't mess around: figure out the right size.

Show some personality
There's one more thing to remember when going out on the hunt for the perfect sexy outfit: the lingerie you decide to buy is ultimately for both of you, but if you're buying for your partner, make sure it's something that person will be comfortable wearing.

Getting her something a little sexier than usual is perfect, but don't be selfish and go overboard. "If your girlfriend's underwear drawer is full of plain cotton bras and modest panties, it's not a good idea to buy her a leather dominatrix outfit," said Snow. "She has to feel sexy and comfortable in it, otherwise it will suck for both of you. All the sexiness will be gone."

Even if you're buying for yourself, it's probably a good idea to keep your partner's preferences in mind as well. You wouldn't want to buy a skimpy schoolgirl outfit for yourself if your partner isn't overly adventurous.

It's also a good idea to check out what the current styles are. Websites like victoriassecret.com or lasenza.com are a good place to start when looking for up-to-date ideas. Salespeople will also have some great tips when looking for something cute and current.

Now that you have a little extra knowledge, you'll be able to find that perfect little something for that special someone or even for yourself.

There are three key groups of lingerie:

Babydolls & Bustiers:
A bit more on the modest side, babydolls and bustiers feature straps, lace and the benefit of full support and more coverage. Most of these items cost around $50.

Bra and Panty Sets:
A flirty bra and panty set is a great idea if you or your partner isn't into wearing anything super sexy or revealing in bed. Because there's such a wide variety of bras and panties to choose from, the cost can start around $30 and go up to $100 for a fancier set.

Costume Lingerie:
Bringing costumes into the bedroom is a fantastic choice for more confident couples. Sexy maids, schoolgirls and dominatrixes all scream sexuality. The average price falls into the $75 range.