A typical bedroom, full of stuff, will absorb and reflect in ways that are decent diffusion...a book case with books stacked higgledy piggledy on the wall directly behind you works wonders.
Avoid working in corners.
Avoid putting speakers in corners.
Avoid closets...there're a squillion reasons for this.
As good a, non usb, mic as you can afford, a decent interface, a pop screen and reflection shield are always handy, a pencil & rubber band.
Experiment.

Cheers
rayc
"What's so funny about peace, love & understanding?" - N.Lowe