the most fun i have is catching things. crayfish are the easiest, you can use your hands or a dipnet, slowly lift rocks not to stir the mud, place net/hand open palmed behind them slowly... then scare them backwards onto your hand or net. fish are a bit harder but u can always make a formation of rocks that funnel towards a net, cage or enclosure(so u can net them). find the fish and slowly steer it toward the funnel (cutting off escape routes . ive caught several 1" bass in a small peanutbutter jar in my hand. it did take several hours though. if you study their behaviour and how they react to things it isnt hard to do, but it takes patience and perserverance. if you plan to keep them id say do research on them(how to care for them they can get big fast) first and catch them later in the summer(the water is warmer). Plan for when they are adults.