What is the "better / best " method to multi-boot different OSes natively WITHOUT VirtualBox(es) ?

[TheBigBlue Guard]

Yes ...everyone...What is the "better /best and least expensive " method(s)
to mult-boot different OSes natively WITHOUT virtual boxes like VirtualPC
or DOSBox etc. I was seriously thinking about mult-booting 5-6 different
operating systems including freeBSD.....

Thanks for reading this

Sincerely,

BigBlue