Basal bolus is a more accurate way of dosing than sliding scale.
In basal bolus dosing, you adjust your basal insulin (lantus) to keep you steady when you don’t eat. Then you dose your bolus (fast acting) insulin to correct (correction dose) for any high blood sugar and to cover the carbs that you are eating (carbs / food dose). After some experimentation you will come up with your own ratios for how many grams of carbs (and protein) are covered by 1 unit of insulin.
Think Like a Pancreas can explain the basics of this, and how to start testing for this.
Dr. Richard Bernstein at “Bernstein Diabetes University” on U-tube also has a lot of sessions about how to dose insulin. He is also a strong proponent of eating low carb to help control blood sugars and to minimize the amount of insulin that is required (less carbs = less insulin = less risk of both high and low blood sugars, otherwise known as “the law of small numbers”)