When using the knotless knot always test the strength of the knot by pulling tightly. Using 3 turns as you reverse back down the shank then through the hook eye helps to eliminate slippage. For total security add a drop of super-glue.
It is vital that you check your hook and end tackle after every cast. Time and again I have witnessed anglers re-cast without checking their end tackle only to hook a carp and lose it due to the hook being a little blunt which inhibits good penetration. When using bottom baits use a pattern which was designed for the purpose. The same can be said of pop-ups. Replacing hooks often is a vital part of the carp fishing jig sore as you will never get the chemically sharpened points as sharp as when they are new by using a hook sharpening stone etc.
Manufacturers are constantly releasing the newest best carp line since sliced bread. Don't be mislead into thinking they are all great. While many are very good, many are not. Sticking with reliable and sometimes cheap lines can pay you dividends in the future both in your pocket and fish on the bank. A couple of my favourites which have never let me down are Daiwa Sensor and Berkeley Big Game. Daiwa Sensor costs just £6.99 and Big Game is only £12.50. Both are extremely good value and neither will let you down in the 15lb breaking strain.
Caring for carp is for most Carp Fishermen is of the upper most importance. Always use an unhooking mat to protect the fish from hard or rough ground. Always apply Klinik or the excellent Korda carp care fluids to hook holes and abrasions.
Always roll the landing net right down to the fish before lifting and check that their pectoral fins are laying flat against the body to avoid them being snapped or cut. When you do hook a carp try to remain calm and controlled, don't panic as that is when you may harm the fish. If you are uncertain about how to handle a carp call for some-one more experienced. Remember though by all means take a picture but always remember that putting a fish at risk of damage is not worth it just to obtain a trophy shot. Read more about the care and welfare of carp here