Tip? The simplest of underhand of assisted lobs that might be termed "Wallis Cast Lite" by someone who likes to call things names but is called nothing by someone wiser who knows that calling anything "Wallis Cast" scrambles both the user's brain and reel, resulting in some interesting tangles.
Just wind your bait in, swing the lead in to your winding hand (leaving the bait dangling below), place the "V" between your thumb and first finger of the same hand over the line just above the reel, transferring as you do so the lead to the same thumb-tip and fingertip, then, with the rod held a little below straight in front of you, drop the lead, lift the rod gently causing the lead and bait to pendulum out river-ward, and at the very same moment gently sweeping back your "line-trapping hand" a foot or so to set the reel spinning a little. Out goes the lead and tackle, with the now-spinning reel feeding line to it through the gap between the thumb and first finger of your "line trapping hand", slow the reel drum with the thumb of your rod hand just before the tackle hits the water, then stop completely as it does so.
Same cast can be done without holding the lead, with it just hanging from the rod tip (even as it is being swung in through the air towards you). So quick, so easy, as the weight of the lead and the very short distance that tackle has to be lobbed in many barbel-fishing situations obviates the frequent, early days, birdsnest nightmares of a proper, going for it, light float-tackle, distance Wallis Cast.