Horizontal hoops in a 14th-century corazzina style. These are full
taces, all the way around;
tassets are tace-lets, y'see, and are those shovel-ish shaped things that hang from the taces to give that bit of extra coverage in one spot or another. A great comfort if you're getting hit with lances coming in low. Fashions in tasset fastening varied with the region; England was noted for fastening the tassets a little ways up on the skirt of taces, a hoop or two up from the bottom, while everybody else liked to hang them right off the hem.
Proper tassets would be too advanced for the rest of your gear as shown, which looks pretty 14th-century except for the Imperial Stormtrooper bits -- also said to be long ago... okay, enough.
The hoops are in two halves, front half overlapping back half just a bit. Suspended, of course, as for spaudlers, upon interior leathers, distributed all round -- 3 front, 3 back should be fine. If you're using thin leather, go 4 or 5, or wider straps even. Make those straps big enough, you can probably repurpose that garment-weight you've got there already. Or fold 'em over double if you must. (I have no idea what leather you may have lying around.)
With your center-front opening that also testifies you've gained a few pounds since making that pair-o'-plates, things become a touch trickier, but not much. (Or is that thing essentially an all-round body bracelet secured to a leather vest?) You may end up putting a non-historical center split down the front of your fauld of hoops and fastening it with a couple of buckles to keep it where you want it. I don't think you'd need more than that if you're using leather strap of at least 7-8oz weight.
Is that white bit of whatever peeping out from behind your lefthand plate an armor part? It's the same color as your legs.
So, summing up: think horizontal hoops, overlapping upwards, 2.5-3" wide, likely no wider. Three or four of them, if not five -- figure how much overlap you want but I wouldn't try the many-loops early-fifteenth fauld with what you have -- those went to approaching mid thigh, all the way down from the bellybutton. Slight dishing of each hoop with a rawhide hammer, a big hammer gently used, or a rubber mallet to conform the hoops to your sexy ole hips -- a bit of compound curvature does absolute wonders for fitting steel to people, and let's face it, everything around there is complex curvatures. You don't even really need a stump for that job, just a bare patch of hard dirt would do, and wipe 'er down afterwards. Number or ABC your taces for their sequence top to bottom so you don't mix them up if you get tired or distracted; by the time they are curved, dished, and satisfactorily fitted they are all going to be a little bit different from each other and are only going to nest right in one sequence. The bottommost tace will have the least dishing, or perhaps none at all; not a big deal there. Punch holes, rivet, fender washers either bought or cut out at home from scrap metal (which is more period anyway, perfectly circular washers being an Industrial Age dating feature) upon the leathers, clinch all together, and fasten to your pair-o'-plates. Instant late-fourteenth style. Do you use a bascinet?