I think it's foolish to buy someone clothes as a present, unless they've specifically told you what to buy. Honestly, in between sizing issues (yeah, I'd love to go exchange this present at the mall along with a million other people) and differences in taste, you're better off gifting straight cash yo.
That being said, if you absolutely have to buy fashion items, stick to a few basic rules: accessories are better than clothes, sweaters and other stretchy/loose items are better than structured items, chance on the side of too small if you're unsure of the recipient's size, and don't be offended if the person does return your gift (because she probably will).
1.) Marlies Dekkers is my favorite lingerine maker. Obviously, I can't afford La Perla or Agent Provocateur yet, but Marlies Dekkers is probably better. I just love the little touches she adds to her lingerie. It's a bit Fifty Shades of Gray, but also wearable by a regular woman. I find her bras and panties to be true to size, so just rummage through her underwear drawer to get a good idea.
2.) Okay, these are a fantastic idea. Does your lady love shoes? But is she limited on space? Piling her shoes to the ceiling? This is the solution! These shoe clips can transform any pair of shoes. These clips are from a Lulu Frost collaboration with J. Crew and they are honestly the best things on the J. Crew website right now. These would look good on flats and pumps and, while pricey, are probably cheaper than buying a ton of new shoes.
3.) My favorite store for affordable, gorgeous cashmere is Club Monaco. Their sweaters are soft and warm and beautiful. This particular sweater has leather trim and the black is great--because laundering cashmere can be a real bitch.
4.) Coach is really getting their shit together. I always thought of it as a "high schooler" brand, but lately, their stuff is looking more polished and more structured. I love their Borough Bag, it's professional and yet totally stylish. What a good way to carry documents to and from the office.