First, make sure your diet is OK with low-carbs and sensible portion sizes so that your weight is OK. Next get your Basal insulin right; one simple way being to have a fasting sugar level between 5 to 7 mmol. Next get your Bolus right. If you aren't yet carb counting seek advice from your diabetes team or if you haven't one then come back on the T1 forum for guidance. When carb counting, find out what your Bolus carb ratio is; typically you would start with 1 shot to 10gm carbs. You must measure frequently if changing insulin dosage and do it a small bit at a time.