My sweet tooth is satiated by a good cup of english black tea (with skim milk a teaspoon or two of sugar). My mum hooked me on it at age 10. I know exactly how much sugar in it, which is good.
I keep reading that you can reward yourself by abstaining all week, then giving yourself one weekend day you can have your absolute favourite snack. Don't know how well we could all keep to that though.
My simplest solution is to simply not buy the stuff, not let it in the house. I've gone months, even years without eating certain junk foods because I stopped buying it for so long it's no longer an attractive food to me. If they do end up in the house however...
Make them hard to get at! Not in the main pantry, but hidden in the back of a cupboard or on a high shelf. The less I see my snack foods, the less I think about them, and less often I go for them. Personal example: Lately I've been horrid at controlling my popcorn eating. The popcorn container was sitting on the counter right beside the popper, given it easy access so I was eating it everyday. I moved the container to the basement pantry, and I haven't eaten any since. The work that it would take to go get it has discouraged me.
I like to break my potato chips into smaller pieces, down to the size of a large coin. Then I make sure I eat them one or two at a time, not huge handfuls. It makes the little bowl last a lot longer. Never eat out of the big bag/container you bought the stuff in. In my house we have bowls smaller than cereal sized that I use for snacks: icecream, chips, pretzels etc. I also will repackage a snack food into those snack sized ziploc bags as soon as I buy it, and only allow myself to eat the bagged amount. I usually use that for the lunch I pack to work.
But, of course my absolute fail safe is to not buy the stuff in the first place. I'm on a shoestring budget so it's pretty easy. All I can think about is how that money can instead go to BM supplies or things I'm saving up for, and I stop myself.

This post ended up longer than I expected, I rambled a bit so I hope it's coherent.