Use every square inch of luggage space. Stuff your socks into your shoes. Roll up sweaters and underwear in the corners of your suitcase. Try to pack your clothes in sealable plastic bags, in case you have to open your suitcase at the customs and do not wish to expose personal items. Pack only as many toiletry articles as you will use.
Small samples are excellent.
Liquids travel best in plastic containers, but don't fill them to the top. Seal them with tape, place them in a sealable plastic bag and pack tape to reseal them later. Always keep in mind that you can purchase toiletries during your program abroad. Do not pack anything fragile, valuable or perishable. Leave expensive jewelry at home.