(notso)lardylady is right, but I see what you mean. I'm 3 months into the plan and also avoid chocolate and crisps, but I haven't banned them. I know I can eat them if I really want to using my syns, but not doing so has really helped me get into the habit of choosing fruit over chocolate, even if I have syns left. It just depends on the person really. If you try not eating chocolate/crisps and find yourself really missing them, don't feel bad if you do decide to make it a daily treat.
I know you said one's that aren't chocolate, but what about drinks, like hot chocolate? I have a hot chocolate pretty much every day, and mix it with skimmed milk which I use as my healthy extra a. So it's 2 syns for a Cadbury Highlights hot chocolate, and you're getting your calcium!
There are other soft drinks like J2O, which are typically 3.5 - 4.5 syns per bottle.
I tend to use a lot of my syns in my meals. I'm awful at cooking rice, so just use packet rice to go alongside my homemade curries, which is typically 3-4 syns. Other food items would be butter for my jackets/mash, WeightWatcher sausages (just 0.5 syns per sausage).
Syns really are supposed to be something you enjoy though, so I wouldn't recommend using them for the sake of it. There will be plenty of things you enjoy which contain syns that before Slimming World, you'd enjoy with your meals (e.g. naan bread, gravy, yorkshire puddings), so maybe just think of those too?