The safest way to secure a bundle with rope is to use a combination of appropriate knots and techniques to ensure stability and security. Start by selecting the right type of rope for the task, considering factors like strength, flexibility, and resistance to environmental conditions. 
Begin with the Clove Hitch knot to anchor the rope to a fixed point or the bundle itself. This knot is easy to tie and adjust, providing a secure starting point. Next, use the Square Knot (Reef Knot) to join two ends of the rope if needed. This knot is reliable for binding and is easy to untie after the load is secured.
For additional security, employ the Trucker's Hitch, which allows you to create a pulley effect to tighten the rope around the bundle. This knot provides mechanical advantage, ensuring the rope is taut and the bundle is tightly secured. 
To prevent slippage, finish with a Bowline Knot, which creates a fixed loop at the end of the rope. This knot is strong and stable, ensuring the rope remains in place under tension. 
Throughout the process, ensure the rope is evenly distributed around the bundle to avoid uneven pressure points that could cause damage or instability. Double-check all knots for tightness and security, and consider using additional securing methods like bungee cords or straps for extra stability if necessary.
Finally, regularly inspect the rope and knots for wear and tear, especially if the bundle is to be transported or stored for an extended period. This comprehensive approach ensures the bundle is safely and securely fastened.