This trail looks awsome
Code:
new colorArray[4];
            colorArray[0]=255;
            colorArray[1]=0;
            colorArray[2]=0;
            colorArray[3]=255;
            TE_SetupBeamFollow(entity, NadeSprite,    0, 1.0, 10.0, 10.0, 5, colorArray);
            TE_SendToAll();
            colorArray[1]=255;
            colorArray[2]=255;
            TE_SetupBeamFollow(entity, NadeSprite,    0, 1.0, 5.0, 5.0, 5, colorArray);
            TE_SendToAll();
Code:
NadeSprite = PrecacheModel("materials/sprites/crystal_beam1.vmt");