1. One thing at a time
   - in small stages, piecemeal, step-by-step, stepwise

1. A little bit at a time
   - piecemeal, little by little, in stages 
2. In a gradual manner
   - gradually, step by step

See also: gradual

• yellow-blue colour blindness
• yellow-blue dichromacy
• yellow-breasted bunting
• yellow-breasted chat
• yellow-brown
• yellow-crowned night heron
• yellow-dog contract
• yellow-eyed grass
• yellow-eyed grass family
• yellow-fever mosquito
• yellow-gray
• yellow-green algae
• yellow-grey
• yellow-leaf sickle pine
• yellow-marked
• yellow-orange
• yellow-shafted flicker
• yellow-spotted
• yellow-striped
• yellow-throated marten
• yellow-tinged
• yellow-tipped
• yellow-white
• yellowbelly marmot
• yellowbird