A nice pair of trousers or pants should follow the same guidelines as for jeans. Boot cut, straight leg, wide leg, or trouser cut pants in quick drying fabrics will serve you best. Avoid overly high or overly low rises, slightly below the natural waistline compliments most figures. Hemlines should be as long as possible without actually touching the ground to give the body the longest line and mask our less than sexy walking shoes. Finding pants in a synthetic blend will minimize bulk and drying time.
Dark neutrals work best to conceal any spots or spills that might happen during the course of your trip. Black, brown, and grey coordinate with other neutrals as well as brighter colors. Khaki’s are a strictly American phenomenon so stick to the darker neutrals. Also save those nifty pants that have zip off legs for when you’re trekking through a rainforest. 
Layering tights or silk long john underwear under pants during cold weather help keep you warm. Wool pants usually need to be dry cleaned, making them less than ideal-save them for the boardroom. In the summer, tailored linen trousers offer a fashion savvy option.
During warmer weather Capri, cropped, or gaucho pants provide an alternative to skirts or shorts.  My problem with capri’s is that they can look way too casual and they are way too ubiquitous. If you go with capri’s at least make sure they are black (NOT KHAKI)
Cropped pants tend to shorten you visually unless you are quite tall, full length pants provide the most flattering length of pant. Your footwear will also be more prominent since we loose the benefit of hiding our sensible shoes under a full length pant. However, for those of you that still insist on a shorter length pant a fitted, dressy, or tunic top can elevate the look to a more Jackie O sense of St. Tropez sophistication.
If you are slender, lucky you, you can pull off a slim cut Capri. Paired with a cute top -voila! If you are less than slender you can also sport the look with a tunic top.
A wide or straight cut cropped pant conveys casual elegance as well as balancing a fuller figure.  There are even wide cut cropped pants with a comfortable elastic waist. The wide cut skims beautifully over the body. Balance the wide cut with a fitted or structured top. A tunic hides a multitude of sins and looks Riviera worthy.