You've already received some good advice; I'm echoing some of it, but I have a few new thoughts:
- You don't say that you'll need to dress up, so that excuses you from a whole category of clothing. This is a big help.
- Since "diva" is part of your name, I'm assuming you're female. Keep in mind that accessories (scarves and jewelry, for example) take up little space but add a good punch to an outfit.
- I'd wear one pair of super-comfortable basic jeans ... and pack a pair of dark-neutral pants (I'd probably go grey, but you might prefer black or khaki -- any of these would work with many tops) ... and pack a simple skirt. This will take care of your "bottom needs".
- For tops, I'd pack/wear 6 simple shirts ... half long sleeved, half short sleeved ... plus two cardigan sweaters (preferably in a mottled color or pattern ... one thick, one thin) that will work with all these shirts. Make sure one of these tops is the same color as your simple skirt so it will pass as a dress. I know that people often suggest that you stick to a color scheme, but I don't see the point -- as long as your tops match the pants and sweaters, you're good for each day.
- Pack 6 pair of basic socks and pair of tights to match the skirt.
- I'd wear a pair of very comfortable black or brown penny loafer-type shoes ... and pack a pair of hiking boots ... and pack a pair of those almost-nothing folding bedroom slippers so you can get out of your "day shoes" yet still walk around the hotel without being in your sock-feet.
- Include one mid-weight wrap, which can serve as a small blanket on the plane or can be used as a layer-over-cardigan. Make the color very basic.
- I'd pack two pair of thin yoga pants + two oversized tee-shirts to wear in the hotel rooms at night. I say two sets because at some point you're going to wash them, and this will allow one pair to be wet ... yet you don't have to be naked.
The above gives you 16 pieces of clothing (3 bottoms, 6 tops, 3 warm items) ... and doesn't include undergarments and socks. Depending upon your destination, you might want a thin raincoat. I'd be perfectly comfortable with this quantity of clothing for a couple weeks.
- Assuming no accidents or super-sweaty days, I'd say the pants can each be worn three days ... so halfway through the trip I'd plan to send out the pants to be washed at the hotel. Yes, it'll be expensive, but washing pants in the sink isn't realistic.
- I've seen this item:
https://smile.amazon.com/Scrubba-Portable-Laundry-System-Light/dp/B00BUI7HFC/ref=sr_1_1?ie=UTF8&qid=1504544270&sr=8-1&keywords=scrubba+wash+bag And I'm thinking of buying it for trips. I think it would be more effective than washing things in the sink. Yeah, the cost is why I haven't bought it yet -- but assuming it lasts and could be used for many trips in the future, it would "pay off" in terms of lighter packing and avoidance of hotel washing costs. I'm a little fussy over my shampoo, so I tend to bring my own ... and use the hotel stuff to wash clothes. Consider packing a sham-wow (the things you use for drying a car) ... roll up your wet clothes in one of these, and you'll find that they really suck up the water ... yet they dry fast too.
- With hostels a possibility, don't neglect to pack a lock ... often places like this provide you with a locker.
- Don't neglect your over-the-counter medicines.
- And pack a couple big ziplock bags in case your clothes aren't quite dry, yet it's time for you to leave your hotel.