Either make more loops, or change one loop
- adding cells or batteries in series increases the current
- adding cells or batteries in parallel makes them last longer
- adding resistors or bulbs to a single loop (so necessarily with series connections) decreases the current in the battery
- adding loops by adding more resistors or bulbs using parallel connections increases the current in the battery
In each case the current is set by the push provided by the batteries and the resistance of the other elements in the loops.