Frosting: To frost a glass, dip it in water and put it into the freezer for an hour or so. Never pour a hot drink into a frosted glass.
Salting: To salt the rim of a glass, rub a fresh cut wedge of lemon or lime around the rim. Keep a shallow tray about 1 cm (3/4 inch) deep with salt, and invert the glass and dip gently into the salt. Move the glass gently from side to side, but do not spin quickly or the salt will simply absorb the citrus and fall off the glass. Use rock salt or sea salt for the absolute best in flavor.
Floating/Layering: While perusing drink recipes, you will often see the phrase "Float (liquor) on top". This refers to adding the liquor so that there is no turbulence and mixing of the drink - the new liquor will be a distinct seperate layer sitting on top of the other components of the cocktail. The easiest way to float one liquor on top of another is to use a medium sized syringe. Obviously this may not be available or desirable, so the common method is to use a spoon, holding it in the glass and slowly trickling the ingredient over the back of the spoon. If no spoon is available, it can be done by slowly pouring down the side of a glass (or alternately, pour down a stir stick that is touching the side of the glass.) Layering is a difficult business. For step-by-step instructions on how to do it, see separate article on how to layer alcohols.
Making cracked ice: To get professional quality cracked ice, buy an ice machine or purchase cracked ice from the store. However, a weak substitution can be made, depending on your ice cubes. If you have the old-school 12-cube trays that produce large, trapezoidahedral "cubes", then empty a few trays into a bag or dish towel. Lay the cubes out on a board or counter so that there is only a single layer of cubes, and whack them firmly with a frying pan, meat tenderizer or mallet. Each cube should only be broken once or twice. If you have the good, multiple small-cube trays, then cracked ice is more easily made. Fill the trays and put them in the freezer. Check on them periodically - once they are near frozen but still liquid inside, shake them and break them a little bit. Freeze once more - when they are almost ready again, do the same but transfer them into an "ice service" tray and discard the excess water. This will give the cubes an irregular cracked texture.
Making crushed ice: Knowing when to crush ice and knowing when to blend it is difficult. Many recipes call for "crushed ice" in terms of making a slushy drink, while other call for it in terms of adding slivers of ice to the drink. If you blend a drink into a slushy drink, break the cubes up (as above) before adding them to the blender - this will save your blender much wear and tear. If you are expecting to make slushy drinks at an occasion, break the ice up prior to your guests arriving.
Shaking: Shaking is simply done with a bar shaker. About 10 shakes is all that is necessary, overdoing it is futile. However, if egg whites or creamy liquers/mixers are called for, triple the number of shakes you think is necessary. These must be well shaken to produce the desired effects. Never use makeshift shakers - two glasses, one upside down over the other, is an extremely bad idea - the rims of the glasses break and drop glass shards into the mix (not to mention they leak).