Snus flavors vary greatly depending on the preparation more than anything else. To make snus, the first thing is to get some dried tobacco leaves and finely grind and sift them until you have a powder. Add equal parts tobacco powder and water with a pinch of salt per 100g or so of the mix, and cook at 55-85C for 1-5 days, then add a heaped tablespoon of sodium carbonate. At this point, your snus will need at least a week for the chemical reaction to complete, but in the meantime, you can now add the flavour or flavours of your choice.
How-tos of combining snus flavors
Here, we have to take a page from gastronomy. Certain flavours go better more so than others naturally. As a general rule, whatever would go well together in cooking would go well in snus. So, for example, combining different types of berries works really well. Also, combining citrus flavours, like lemon, lime and/or orange works as well. Strawberry and banana is a classic combination used in things like gum that would work well in snus. The only real difference between traditional chewing gum and snus is that with snus we have to have stronger flavours because of the nicotine present.
Types of Snus flavours
For this reason, snus flavours tend to be either strong citrus flavours or minty flavours. Liquorice is known for being one of the strongest flavours out there and is very popular because it goes well with a lot of fruit flavours. Combining fruit with mint or liquorice is generally going to yield you some very positive results for this reason. Also consider adding spices like cinnamon or cloves, which are also very strong and biting flavours, serve to compliment and mask the ever-present nicotine. You could start by combining a fruit with a spice, like apple cinnamon (which is an amazing combination in and of itself).