I'd try one of the following
1 In well drained compost (add some grit and to counter the additional weight maybe a small number of small bits of polystyrene) use some thyme for the trailing plants - the non-variegated seem to flower better (will need full sun on them and won't flourish at the back of the basket). Also a small lavender (English or French lavendula) or two and some pot marjoram. For a splash of colour some calendula (keep some seed back and grow another few in individual cells to replace when the first have ceased flowering). Or Instead of the pastel coloured marjoram you could sow some limnanthes, that is great for bees.
2 In ordinary compost you could sow calendula, emilia Irish poet, flax (all easy from seed) and possibly also some candytuft and night scented stock. The latter may attract moths but in any case will give a welcoming scent by your door. You could dot in some chives for colour contrast. Not sure about bee-friendly trailers - maybe nasturtium? The height may help tp reduce aphid infestation. Someone else may come up with something better for trailers in ordinary compost.
If you want something more pastel, try candytuft with night scented stock and some sweet scabious and/or nigella. I find sweet scabious best started off one per sowing cell until established rather than sowing direct. Again not entirely sure about bee friendly trailers.
Haven't tried these combinations in a basket myself but they should work well.