Getting to the OP, it would seem to be advice on trolley landings? All ours were marked fore and aft with skid lines to give reference when lining up from behind, then a marking to where the cross beam should be when on the trolley.
Always approach from well behind and 'hover taxi' into the trolley keeping a reference ahead that aligns your eye view to where the skids should be: don't over-reference the markings at this stage.The reference may vary day to day depending on where the trolley is parked. When at the approximate position fwd, look out to ensure the skid is aligned and the crosstube is up to the appropriate mark, then down on the collective while using the yaw pedals to keep aligned with the fore and aft lines. Practice makes perfect, but a smaller trolley will inevitably cause loss of reference when the nose of the machine goes over the front!
Aids already mentioned (if it's a small trolley) are the glassfibre rods either side of the eye line, but cap the tips: one pilot at Essendon managed to punch the tip of one rod through the side window of an AS355.
All my pilots would have little problem aligning the machine this way, even my non-SAS BK117 could be plonked onto the right spot time after time. If the approach is tight and a more vertical approach needed, then kick off to the left to give a better downward vis out of the side window, then pedal turn to straighten up when a few inches off the deck.
Re SASless' tale of derring-do in a BK, we would carry out lighting checks at night for Melbourne Airport in the BK117, requiring OGE hover with small moves to check the TVASIs and other approach lighting. Talk about being in a black hole out to the west with absolutely no ambient light!