Last 'posh' canapes I did were those Thai bites mini biscuits with a mix of creme fraich and chives on some and creme fraich/sun-dried tomatos on others. Topped with shreds of chive/sundired toms. Also 1/2 cherry tomato and baby mozaerlla balls (or cut up big mozzarella balls) on cocktail sticks, drizzle over pesto. Smoked salmon on brown bread, cut into mini squares. Ham/smoked salmon and cream cheese pin wheel sandwiches. Roll bread with a rolling pin, spread with cream cheese, top with wafer thin sliced salmon or ham, and roll up. Cut into slices. Shop bought crostini toppped with tzatzki and king prawns, scatter over corriander to look fab. You can also buy tiny little crispy 'cups' that can be filled with various fillings like cream cheese, or creme fraiche or whatever. Tiny finger sanwiches, crisps and dips, veggies stick too. mini bread sticks. Olives, nice nuts, mini spicey popadoms and dips. You need about 6 - 8 canapes per person plus crips/dips.
HTH I find the important thing is what they are transrported to the mouth on!! eg get a couple of packs of thai bites, crostinis, baby canape cup things, a loaf of bread. Then it is combinations of creme frache, fromage frais, cream cheese and various flavourings. Pesto mixes well with any of those, as does olive tapenade, sun dried tomaot, herbs etc tec. Mix a load of toppings, cut up a load of garnishes (long strips chives, sundried tomatoes - I cut everything with clean scissors and prep the night before into little tubs) Then it is easy, lay out the platter of bases, dollop on the toppings, add a garnish and srpinkle whole patter with fresh herbs. Looks classy and professional