Many people here use a magnetic stir plate to mix but there is far more to DYI then just stiring. Let me recommend some research and welcome to the forums.
My blogs will give insight into all aspects of DYI, from steeping to what supplies to have on hand to a basic walk
through mixing your first E-
juice.
E-Cigarette Forum - dannyv45 - Blogs
Then read hoosier's blogs. These blogs concentrate on fine tuning your mix and give insight on additives.
E-Cigarette Forum - Hoosier - Blogs
Then read Boletus's blog's. These blogs concentrate on formulation of nicotine bases regarding proper calculations methods for figuring Nicotine concentration as well as safety.
E-Cigarette Forum - Boletus - Blogs
Then read Ginger's book "E-Cigarettes 102: DIY E-Liquid". It is a book which I've contributed to that delivers an in depth easy to follow guide in the art of DYI.
E-Cigarettes 102: DIY E-Liquid
I recommend viewing VPLive Vape Team Episode #82: DIY Safety and bookmark it for future reference. It explains safety in all aspects of DYI.
VPLive Vape Team Episode #82: DIY Safety
then read the stickies at the top of the page.
this will explain a lot of the how's and why's.