ok, ill try but not so good at explaining.
standard four string, square scoubi.
say we have two scoubi strings. one green. one red. hold them together and fold in the middle.
so now you have four ends in one hand and the folded end in the other.
make a knot in the folded end, leaving a little loop there of the one red and one green.
now take the knot in your hand. arrange your now four strands into north, east, south and west. north and south being say red, east and west being green. bring north (red) towards you forming a loop on the left and take south (red) away from you forming a loop on the right. hold them in place.
now take east (green) over south red and under north red on the top, then west (green) over north red and under south red on the bottom.
this should make your square, then you continue just the same.
its easier than it sounds, honest!!