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

• poori
• poorly
• poorness
• poorwill
• Pooterish
• pootle
• poove
• pop
• Pop Art
• pop bottle
• pop group
• pop in
• pop music
• pop off
• pop one's clogs
• pop out
• pop quiz
• pop tent
• pop the question
• pop-fly
• pop-up
• pop-up book
• popadom
• popadum
• popcorn