The basic of tethering without the tether plan on your account:
Use a different app to initialize the access point than what is included in the Stock OS.
A plethora (a great amount) of options need to be toggled, through different means than Stock OS methods.
Some, most, all, none specific setups need tweaking to specific settings. (I used most of this guide on my Huawei Valiant with great success)
Important: You need to be mindful on what you are doing. Yes, most options that are toggled to activate the access point need to be applied upon every use of the access point. Yes, these are 'extra steps' compared to paying $5/month. Is that $5 worth it? After 2 months, I decided 'No'. You may choose otherwise.
By the way, I had rigged a script to apply my needed toggles. If you are any kind of coder (I am NOT), you could do the same.
Choice of web browser on PC side matters depending on how you hide the PC data, AND the websites you visit.
I can use the Hotspot app in this thread WITHOUT TOGGLES (just turn it on) to give internet to my tablets. No warning banner or redirects. My tab is Nexus 7, wifey has iPad. BUT, to get my Vista laptop onit requires the toggling of crap.
Methinks I've contributed all I can to this thread.... lol
Good luck, just follow all the steps. If you get stck, post back.