How old is he? AE and A&F seem very teenage to me...which is fine if he's a teenager, but if he works from home I'm assuming he isn't.

He's 25, but could pass for younger. Hmm...I know a few guys in their early 30s who wear AE and A&F and they seem to pull it off well so I've never thought of it as teenage, but maybe that's because they aren't head to toe?

Example:
http://erniehaase.musiccitynet....._35653.jpg

Hannah, How tall is your brother and what size is he wearing? If he is slim, but tall, and you say his shirts are too baggy on him, my guess is he's not wearing the right size because he needs the length. Which means he needs to shop for tall sizes. Gap carries men's tall in a lot of their styles.

Does he know you are on a quest to help him dress better? If so, then start by measuring him. Measure his height, chest, waist, inseam, arms and neck. Then compare his measurements to size charts online at stores like Gap.

Nicole, he's around 5' 9", so actually he's on the shorter side for a guy. He wears a size small in shirts, but you know how that works - fit depends on the brand. He's fine with me helping as long as he doesn't have to spend hours at the mall trying things on. Good thought on the measurements, I'll do that.

Hannah, if he's 5'9" but has a very short inseam then he could have a long torso and need a tall shirt. It's not impossible to be a small tall. Also, is he broad shouldered? He could need an athletic cut, which would be broader at teh shoulders and tapers in at the waist.

The fact that he is wearing size Small but still has baggy shirts tells me he's probably not a standard size.

Two things really stuck out at me in reading your post: plaid flannel shirts and jean shorts. These just aren't fashionable. I think he definitely needs to toss the jean shorts. If he wants to do something casual for the summer, have him stick with khaki shorts, or even cargo-style shorts (which I like on guys his age).

I would replace the plaid flannel shirts with more basic button-downs. One brand that might work really well for him would be Brooks Brothers non-iron shirts in slim cut. The slim cut should make them fit better and the non-iron will mean he can just wash and throw it on--no ironing required. But he will look SO much more polished. They come in solids and patterns (including plaids, but nice, subtle plaids, not your typical lumberjack type with bright colors). My boyfriend wears these shirts to work with his wool pants, but then also wears them on weekends with shorts or jeans, and they always look great.

Here is a link to the options: http://www.brooksbrothers.com/.....ion_Id=205 You have to imagine it without the tie, of course, and some of the styles are stuffier than others, but you have to make the right choices.

As for the sweatshirts, could he be convinced to wear some finer guage sweaters instead? Or some polo shirts?

Finally, I don't know what kind of sneakers he is wearing, but you may want to upgrade those as well so his footwear looks a little more fashionable. I know a guy who wears plain white sneakers everywhere, and they aren't at all cool or trendy, and it makes his outfits look really unfashionable.

Hannah, my husband is 5'8" and ultra-slim (he's a runner). We have such a hard time finding clothing for him. We absolutely cannot find dress shirts to fit him (we just had a frustrating shopping trip) but casual shirts are fine. I think JCrew's casual shirts are great. http://www.jcrew.com/catalog/c.....=cat301066

My husband and I have gone round and round on his casual style. He is fine with white athletic sneakers paired with jeans, long-sleeve t-shirts or in the summer shorts with t-shirts. I've gotten him to wear these button-downs with dark jeans and casual brown shoes. This takes him everywhere we need to go that isn't dressy.

Check out banana republic and JCrew for more age-appropriate wear for your brother. They carry sizes that will probably fit him.

Thank you ladies for the suggestions! I like some of those JCrew shirts. I will measure him up and see what I can do.

Steph, I'm pretty sure he would do sweaters or some zip-front cardigans ( http://youlookfab.com/2006/11/.....for-gents/ ) if he had some, so long as I remove the other offending items! Polos sound good, too - are those okay in long-sleeve as well as short-sleeve? He has some nicer shirts similar to Brooks Brothers for going out, so I'm mostly trying to improve his at home casual style (we live in the same house, so yes it matters!).

What kind of casual shoe options are there?