It all depends on you, just get any amount you want.

It depends on your style preferences. If you really like certain trendy items and consider them to be (or become) a part of your style, and if you will happily wear them after the trend is "over", then I'll say: Stock up while they are available!

On the other hand, there will will probably be trends that you don't buy into at all, because they are not appealing to you and/or not compatible with your style. And that's fine.

Finally, there may be trends which you just want to try, and in those cases, one item may be more than enough. (Sometimes, it's actually enough to try it on--you may not actually buy it. )

I suppose it depends on how often you want to wear it and how much you like it. I tried one cold shoulder top over the summer and that was more than enough. I just didn't fancy the style. But over the years, I've grown to really enjoy skinny jeans and own multiple pairs that I wear quite often in the winter months with tall boots.

There has not been many trends I say I like lately. Certainly not the "cold shoulder" tops. I happen to think they're hideous, unless you are very elegant with no sun spots, and an actress or real gorgeous gal. To see volumes of women wearing them in cheap fabrics and prints, is really ugly, I think. I haven't bought any tops with bell sleeves because, hey, I have housework to do, and they are simply too impractical and would get in the way of everything! As someone said above, getting caught on a doorknob! Exactly~! Now the shorter ankle length pant, I happen to love, as you show cute socks and a cute loafer worn with them, rather than a pant so long your shoes don't even show. I'm not sure these length pants are a trend, are they? Not sure. But I love them! I think nowadays any length pants are fine, wide, skinny, low, high waisted, whatever looks good on YOU~ That's what we should all buy, what flatters our assets, not trends. Great idea above, someone said to cut off your capris to make shorts! Yes, well bermudas, right above the knee! Great idea! Thank you for that! I have some capris that are mid calf length, and I'm tired of them. Great ideas here ladies