Step 1: Define capacity through a ratio.
Give a conductor charge \(Q\); let its potential become \(V\). The fixed ratio \(C=\dfrac{Q}{V}\) is its capacitance, i.e. the amount of charge needed per unit rise of potential. Unit: farad.
Step 2: What decides its value.
Capacity depends only on the conductor's shape and size, the medium around it, and the presence of nearby conductors, not on \(Q\) or \(V\) separately.
Step 3: Ways to raise it.
\(\bullet\) Make the conductor larger (for a sphere \(C=4\pi\varepsilon_0 R\), so more radius means more \(C\)).
\(\bullet\) Place a grounded conductor close by so induced charge keeps the potential low for the same charge.
\(\bullet\) Surround it with a dielectric medium; a dielectric of constant \(K\) multiplies the capacity by \(K\).
Step 4: Summary.
Anything that lets the conductor store more charge while keeping \(V\) small raises the capacity.
\[\boxed{C=Q/V,\ \text{raised by size, earthed neighbour or dielectric}}\]