1 Plan your menu carefully – make sure you have things that can be finished and plated in advance as well as a few hot items that you can get out of the oven as the evening goes on. I usually work on the principle of 3 hot 3 cold and something sweet.
2 Think about how much your guests are likely to eat. Conventional wisdom says 4-6 pieces of canapé per person, but in my experience people like to try at least one of everything that you serve. I usually calculate 2 of each for people with small appetites, 3 each for everyone else. Still, that’s not a hard and fast rule: I’ve seen actresses and models and picky eaters who stick to diet coke all night wolf 5 cocktail sausages.
3 Are you going to pass round platters of food yourself all night? Can you rope in husbands, sisters, best friends to help? I’m not averse to asking shyer guests to help pass round plates – it can be a less self-conscious way to mingle.
4 Dot bowls of chips, olives, pretzels, nuts, popcorn, M & Ms, strawberries, platters of cheese – whatever suits your style – around the room, so when canapés aren’t being passed people can still reach for sustenance.
5 Let people know the party’s coming to a close by serving a sweet canapé. Store bought brownies cut into quarters and topped with a tiny blob of Nutella are a really simple way of providing a memorable chocolate hit. Pass round a plate of truffles, or open a box of Bendicts Bitter Mints. When we were living in 
Poland I hosted a party for some friends who worked at different embassies. I served a pyramid of Ferrero Rocher. Only the Brits who had seen the commercials found that stylish and funny. Happily, I am a Brit.
6 Look for attractive serving plates – mirrors, tiles, slates, baskets … Think about the kind of food that you are serving. Shot glasses are great for soups, a shrimp looks beautiful on a bed of shredded lettuce in a champagne dish. Consider using Chinese soup spoons, tea cups, espresso cups. Cover ho hum platters with banana leaves. In a push, cardboard box lids covered in tin foil will stand in as serving trays.
7 A cocktail party needs a cocktail. I usually make one in advance and serve from a giant jug into glasses with ice in them. I know that ice dilutes the alcohol and that in an ideal world I would shake the drinks from the jug into a cocktail shaker and thence into the glass – and sometimes, in fairness, my husband volunteers for this – but usually convenience wins out. I also serve wine and fizz, as well as some non-alcoholic options – elderflower cordial diluted with sparkling water, a half and half mix of grapefruit juice and cranberry juice, and lots and lots of plain old water.
8 Gather glasses together ahead of time. Designate a space The Bar and line them up with bottles, jugs, bottle openers, garnishes etc.  To match or not to match? As your aesthetic leads you. Most large wine shops will negotiate glass rental for you if you’re a few short, Ikea can also be your friend here, and if you like a more jumbled vintage vibe, head down to Housing Works or your charity shop of choice and see what you can uncover. My mix and match martini glass collection makes me happy.
9 If you forgot to chill your wine by all means shove it in the freezer – but set a kitchen timer for 40 mins – it will be well chilled, and won’t have cracked open and flooded the shelf with crystalline sludge.
10 If you turn around and discover that your neighbors’ cat got into the kitchen through the window and ate half the canapés, order appetizers from a local Chinese or Indian restaurant (spring rolls, prawn toasts, chicken satay, samosas, bajhis). Dab off excess oil, then keep warm in the oven and serve on your best china or silver, preferably with a bit of herbage snipped on top. Hide the delivery bags. Accept complements when your guests give them to you.