Shopping: Bra, Panties, Bikini?

Shopping for lingerie with a girlfriend is easy... right?
The problem is how to buy lingerie for a non-girlfriend girl friend?

You're a guy, you'd know that...
1) Simply shopping for your own stuff is irritating;
2) Shopping for someone else would be a chore;
3) Shopping for a girl would give you a migraine;
4) Shopping for a Bra/Panty/Bikini set: PRICELESS!

Here's some pointers from me,
"How to shop for lingerie for a non-girlfriend girl friend?"

Figure (no pun intended) out the correct size, how?
a) Call to ask; a little straightforward and if she's fine, great!
b) SMS and hint/probe; more subtle, and you store it in your phone!
c) Look around for "sample size"; totally wierd, but it works if you can point out the "sample sized person" to the sales lady.
d) Show or "Mould" the size using your hands; enough said.
...as long as you succeed with any of the above options, you won't need to repeat it 'cos you'll have the size figured out. I was fortunate with option 2.

Once you have the size, where to buy?
a) Walk around Marina Square; very high concentration of lingerie/bikini shops. My count: at least 6 shops.
b) Walk around Suntec City; adjacent high concentration of lingerie/bikini shops. Not as many as (a) but not too few.
...lingerie shopping, here we come!

Which one to choose?
a) See which colour/design she'll like;
if you have no idea what she'll like, choose something you would like!
b) Texture; which material feels nice against the skin, is not abrasive, not plasticky, not stiff?
c) Material; opaque, translucent, transparent?
d) Design; multi straps, gString/thong, etc
e) Ask a cute babe for her opinion (make sure she's not accompanied by boyfriend); start a lingerie conversation and get her number!
...to be executed in the order stated, except for (d) which i'd recommend regardless of the success of the previous steps.

How to buy?
a) Find the size off the shelf; simple, straightforward, unadventurous
b) Ask the salesperson for help; lazy, incompetent, scaredy-cat
c) Offer to buy that cute babe's items for her if she'll check out your items for you; then tell her you'll help validate her purchases "after office hours"... get her number!
d) Bring the items to the cashier, then swipe your card; no choice
...one/combination of the above would work, but i'd strongly recommend (c) if you've made a good pick.

Happy lingerie shopping guys!