While the 1960s as a whole saw many different fashions come and go, the hippie and natural looks of the late '60s are what usually come to mind when you mention clothing from that decade. That makes finding a costume for a '60s party relatively simple because you can always resort to jeans and a tie-dyed shirt no matter your gender. However, looking at other fashions from those years will provide variation.
Loose and comfortable are the keywords for most of the clothing in the late '60s. Long skirts in earthy colors or with patterns such as flowers and paisley, along with peasant-type blouses, will work for women. Caftans with lace-up necks and long sleeves would be appropriate as well. If you prefer a shorter look, a miniskirt is always an option. For men, vests, T-shirts and jeans, especially in brown or other darker tones, will be fine -- stay away from ties, of course. Both men and women can wear bell-bottom jeans and T-shirts. If you'll be outside, a poncho will keep you warm. Both men and women can wear these.
Shoes and Sandals
Shoes should focus on comfort. Sandals are suitable for both women and men, especially if wearing jeans. For women, boots -- especially tall lace-up boots -- are appropriate for costumes with skirts, though sandals are still all right. Shoes for a man’s costume can range from Chelsea-style zip-up boots for a neater look to moccasins for natural-look or hippie costumes.
Hairstyles and Hair Accessories
For women, a very short pixie cut is acceptable, especially if you're aiming for a neater mid-'60s mod look. Or, if you have long hair, either braid it or let it fall straight down, parted in the middle. A wig will help if you have shorter hair and want the long-haired hippie look. For men, hippie costumes require long, floppy hair -- now is not the time for hairspray. Both genders can adopt the peace-child look with headbands that fit around the head and across the forehead, or flowers to tuck behind an ear.
Makeup and Beyond
The late '60s saw a natural look become a viable alternative to wearing makeup, so women don't have to wear it if they don't want to. Make jewelry chunky; go for either geometric and bold or peace-related with peace signs, flowers, stars and moons. Peace symbol necklaces are appropriate for men, too. Both men and women can carry props, such as flowers and guitars. Get cheap costume sunglasses known as granny glasses -- these are the round ones John Lennon is often pictured wearing.