Here are several suggestions for preventing tantrums:
Try to make sure your child doesn't get too tired or hungry. So if you're going out, plan ahead and take along a snack, or a favourite toy.
If you know you're going somewhere that's going to be boring, make sure you bring along enough things to keep your child occupied.
Let your child know what to expect when you're going out together. For instance, if you're going to the grocery store, let him know in advance that you're not going to be buying any treats, but that you'll let him pick out the kind of cereal to buy.
If you see your child is getting restless, encourage her to talk about what she is feeling - Is she tired? hungry? feeling confined? Encouraging your child to talk about her feelings can help her manage her emotions better, so that she doesn't get overwhelmed.
Basically, once you learn your child's patterns and you're aware of what situations could be possible triggers for tantrums, you can help prevent many blow-ups. But remember, no parent can completely prevent tantrums. Tantrums are a common part of children's development, particularly during toddlerhood.