There is no one definitive answer to this question as everyone's experience with allergies and their triggers is unique. However, there are some general tips that may help to prevent or lessen the severity of allergic reactions.
First, it is important to identify what your specific allergy triggers are. Once you know what substances or situations tend to trigger an allergic reaction in you, you can take steps to avoid them. If you are unsure what your triggers are, consider working with an allergist who can help you identify them through skin prick tests or blood tests.
Second, even if you cannot completely avoid your triggers, you can often minimize your exposure to them by taking certain precautions. For example, if dust is a trigger for you, make sure to keep your home clean and free of dust accumulation. You might also want to invest in a high-quality air filter for your home. If pet dander is a trigger, try not to let pets into your home and keep them out of any rooms where you spend a lot of time (such as bedrooms).
Third, it is also important to be prepared for accidental exposures to allergens. This means carrying around medication (such as an EpiPen) that can quickly mitigate the symptoms of anaphylaxis in case of such an emergency. It is also wise to wear medical identification (such as a bracelet or necklace) that alerts others of your allergies in case you are unable to communicate this information yourself.