Scripts that write themselves.

Remove every unused solid and group all comps into a "Comps" folder.

// Cleanup project treeapp.beginUndoGroup("Cleanup");var folder = app.project.items.addFolder("Comps");for (var i = app.project.items.length; i >= 1; i--) {  var it = app.project.items[i];  if (it instanceof FootageItem && !it.usedIn.length)    it.remove();  else if (it instanceof CompItem)    it.parentFolder = folder;}app.endUndoGroup();

Apply ease-in-out to every keyframe on selected layers.

// Smooth all keyframesvar comp = app.project.activeItem;app.beginUndoGroup("Smooth keys");var ease = new KeyframeEase(0, 66);var sel = comp.selectedLayers;for (var i = 0; i < sel.length; i++) {  var props = sel[i].selectedProperties;  for (var p = 0; p < props.length; p++) {    var pr = props[p];    if (pr.numKeys < 2) continue;    for (var k = 1; k <= pr.numKeys; k++)      pr.setTemporalEaseAtKey(k, [ease], [ease]);  }}

Stagger the start time of selected layers by 4 frames each.

// Frame-stagger selected layersvar comp = app.project.activeItem;app.beginUndoGroup("Stagger");var sel = comp.selectedLayers;var step = comp.frameDuration * 4;for (var i = 0; i < sel.length; i++) {  sel[i].startTime = i * step;}app.endUndoGroup();

Apply loopOut('cycle') to the rotation of selected layers.

// Loop rotation cyclicallyvar comp = app.project.activeItem;app.beginUndoGroup("Loop rotation");var sel = comp.selectedLayers;for (var i = 0; i < sel.length; i++) {  sel[i].transform.rotation.expression =    "loopOut('cycle')";}app.endUndoGroup();

Duplicate "BG_circle" 12 times, arrange in a circle of radius 400.

// 12 copies in a circlevar comp = app.project.activeItem;app.beginUndoGroup("Circle of 12");var src = comp.layer("BG_circle");var cx = comp.width/2, cy = comp.height/2;for (var n = 0; n < 12; n++) {  var d = src.duplicate();  var a = (n / 12) * 2 * Math.PI;  d.transform.position.setValue([    cx + 400 * Math.cos(a),    cy + 400 * Math.sin(a)  ]);}