How to put a strap on securely and comfortably?

To put a strap on securely and comfortably, adjust the strap to the desired length and position on your body. Make sure it is not too tight or too loose. Fasten the strap according to the instructions provided, ensuring it is snug but not constricting. Test the fit by moving around to ensure it is secure and comfortable. Adjust as needed for a proper fit.