👂What kind of methods build quantum computer in my house?

☝From photons and optical components.

👉
We need optical components
that can put photons
into superposition and apply gates.

☝ Using nuclear magnetic resonance

👉
We need the strongest electromagnet
we can buy or build
in order to maximize the signal
we get out of the molecules.

☝By trapping ions

👉
We need a strong enough vacuum,
creating our microwave or laser control setup,
and in creating our Paul trap for trapping ions — perhaps start with trapping dust particles,
and then go from there.