Artistic glass designs don't need to be tough. Many people only have the fundamental skills required to cut pieces of glass to obtain a lamp or fireplace and find that they often violate their glass in places they don't need. Here are some simple ideas that can help you.
First, make sure you don't push too hard. How will you know if you are also ardently cutting your glass patterns? The scoring line will probably be visible and small glass shards could be seen as the cutter wheel runs across the entire surface of the glass.
You can still split the glass on a scoreline but may have problems if the results are not predictable and are with dichroic glass squares.
Don't press too gently either. If you can't hear the dent being created or can't find the scoreline well enough then it will be difficult to break this glass predictably or efficiently. The score here simply isn't deep enough for the glass to go with it, and that means you can expect it to break into weird patterns.
Making them is a company, constant pressure. Some prefer pistol grip pliers because of their better ergonomics. This is a scenario where it pays to spend a little more on a fantastic cutter. Don't forget to press with your entire body, not your wrists, and hold on as your score because you have a much better angle.