Powerbank from laptop battery
Your simplest solution would be all parallel. That way, there's no need for balancing, as there would be with a series string. 

Equalise the voltages before connecting the cells in parallel, connect cells with resistors for a while to do this easily. This is very important, dangerous currents can flow if you connect unequal batteries directly.

Use a fuse per cell when connecting in parallel, to prevent a single battery fault becoming a disaster as the other 5 batteries gang up on it.

A boost converter up to 5v output would be needed from the 4.2 to 3(ish) (depending on your chosen endpoint) voltage range of the cells.

If you only want 5v at 1A, then a single 18650 plus boost converter will meet that requirement. Add more cells to last longer, or for higher current output.