How to doublespace a document

Question

I am writing my thesis in LaTeX, using Overleaf as the site to compile the document. I want to make doublespace between lines.

Can I know: How to set double-spaced text (1-inch margins, 12-point font) in Overleaf? Currently, my text style is:

\ifthenelse{\boolean{PrintVersion}}{
\usepackage[top=1in,bottom=1in,left=0.75in,right=1.25in]{geometry}   % For twoside document
}{
\usepackage[top=1in,bottom=1in,left=0.75in,right=1.25in]{geometry}   % For oneside document
}
\usepackage{amsmath,amssymb,amstext} % Lots of math symbols and environments
\usepackage{graphicx} % For including graphics
\usepackage{nomentbl} 
\makenomenclature
\usepackage{ifpdf}