Ive been trying various forms of marketing. Online, door to door, flyers, bulletins.... sometimes I see results immediately and sometimes I get no response. What are some great forms of marketing where I can at least guarantee some ROI? Or at least feel like I am not completely wasting my time.

The ones you mentioned are pretty good ways it just depends on where and how effectively you are using it. You can also get recommendations from customers to which you have done a good job, maybe offer some bonuses so they can brag about how good you are so more people can come. In the end it all depends on the environment. Try to experiment a bit more

Some form of web marketing maybe? It's kinda doing the job for me and I'd recommend it to other people. Personally I currently am just advertising on facebook and not getting that much out of it but considering I just started I'm guessing it will take a while. You should think about it too

everything you can think of , make sure you try to be creative with the advertising forms and even invent your new of advertising, I've done that and it's been pretty useful though I'd rather not share it here but try to find one

Just to keep it updated after a few months of advertising on facebook I've been doing fantastic, it's definitely worth the time

then you must have found so great method, try some other social websites now

yep I am trying now and I am planning to make it a lot bigger, it's working out that's for sure. Thanks

no probs, if you have any questions you can surely ask here or like you said in some other thread, send me a private message.
Good luck!