Basil is incredibly easy. A 4" stem in a glass of water will produce roots in aout 2 weeks.
Some plants (i.e. willow) prefer to be cloned via hardwood cuttings in autumn.
Bending stems over and planting into the ground is called layering. A good way of propogating many trees.
Then there is 'air-layering' where a branch is 'nicked' then wrapped in a suitable medium and cling film. Good for rubber plants.
Commercial fruit trees are in fact generally grafted or budded onto another root-stock.
I've done air-layering with aluminum foil before. Air-layering has a pretty high success rate, I've found.