Giving injections that contain no more than 7 units of insulin helps the insulin disperse more quickly and can prevent lumps, lipohypertrophy and lipoatrophy. You can of course give as many small shots as you need to cover your basal or meal.
Using long enough needles can also help eg 12 mm.
Putting some pressure on the injection site with a tissue can help immediate extravasation of blood that causes bruises.
I hope these suggestions help.
Katharine.