Interference, capacitance and crosstalk are the main issues with interconnects. Capacitance can be minimised by choosing the right cable (say a quality coaxial cable). Use of a highly capacitive cable may cause instability in the amplifier which can impact the sound adversely.

Crosstalk and interference are eliminated by the use of shielded, coaxial cables. You can make your own interconnects with good-quality audio coaxial cable and connectors. If this is too much of a chore, get the RCA gold series interconnects from Walmart. They retail for about $15-20 for packs of three (usually color coded - but I am yet to come across an amp that is fussy in this respect!) and are difficult to beat.