How do I make my CSS web template compatible with all web hosts?

I have been experimenting with designing CSS web templates with the intention to sell them. I am getting pretty good, but I want to make sure they are compatible with as many hosting sites as possible. Are most standard CSS templates compatible with hosts or is there something else I should be doing? Thanks in [...]

Should I use web design software or web host’s design tools to create my new small business web site?

Easy to use software please, all recommendations appreciated. Software preferably downloadable freeware or shareware & not too expensive.