There isn't really anything to 'learn'. It's a lot more straightforward than you think. Just put your annuals where you want them. Both your examples would cause no problem to a determined daffodil or crocus. Spring bulbs would already be showing by the time you plant out annuals so just avoid breaking them off as you dig. Alternatively, if you are sowing seed just sprinkle it over the bulbs. They'll sort themselves out.

My gardens are designed to have waves of blooms from mid-Spring until fall. It is not really a cottage style, because I do try to maintain some spacing. But there is a lot more packed into my gardens than what appears on the surface at any one time.

The first "wave" of blooms is mostly bulbs and a few early blooming shrubs like Forsythia or Purple sand cherry. Some of the later bulbs will blend with early blooming perennials like Dicentra or Columbine. Most spring bulbs or spring ephemerals are going to bloom long before any winter-sown annuals bloom however. You could buy already blooming annuals at the nursery though, but that defeats the purpose of winter-sowing!

It is the dying bulb foliage that I am usually trying to hide by planting the bulbs amongst the emerging perennials or planting annuals amongst the bulbs. I also try to fill in between perennials with annuals and biennials - Cleome, Cosmos, Verbena bonariensis, Digitalis, some herbs like dill and cilantro which make pretty flowers, etc. Sometimes it works great, sometimes not.

I try to take lots of pictures, so I can go back and see what's blooming when, and constantly refine the waves of blooms in the gardens. Takes years, but it's fun fun!

Hope this at least partially addresses your inquiry.

Examples of bulbs for blooming succession:

February - March - April:
- Snowdrops
- Eranthus hyemalis, cilicica
- Iris - miniatures
- Crocus
- Scilla
- Puschkinia
- Chionodoxa
- Muscari
- Narcissi of all sorts - early - mid- late season
- Tulips - early - mid - late season
- ***Bleeding Heart, Mertensia virginica & Helleborus begin to unfurl***

May - June - July - August:
- Late blooming Tulips & Narcissi
- Anemone blanda
- Gladiolus - both hardy & not hardy kinds
- Camassia
- Brodeiea
- Lillium - (June thru August)
- Ornithogalum
- Lycoris squamigera

September:
- Colchicum
- Fall crocus

- Allium for May - June blooming

These are really wonderful ideas. Continuous blooms is something I've just started trying to work on myself. Thanks for sharing these!