Based on Sefer "Bedikat HaMazon KeHalacha" by Rabbi Moshe Vaya shlita
Dried Dates: Cut lengthwise, remove pit. If you see dark crumbs near the pit - worm droppings - discard. Hold open date against light and check inside and outside for insects. White sugar crystals in old dates are not a sign of infestation.
Fresh Dates: Large dates sold refrigerated, smooth skin, dark brown - generally clean, no need to check.
Pomegranate: Check skin for a hole - sign of worm entry. Open and if you see a brown area, check between seeds for worm. Superficial dark spots on seeds are not infestation. Homegrown pomegranates have high infestation.
Apples: Premium quality apples are considered clean. Medium quality - check skin for worm entry sign - brown-grey wound sunken in peel - remove affected area. Sometimes 'Anna' apples have brown-grey scale insects causing red spots - remove insect with nail/knife, red spot itself is permitted. Imported apples sometimes coated with shellac - question of kashrus, should peel. Check with hechsher.
Kara (Pumpkin): Considered clean, no need to check.
Fresh Lubia (Black-eyed peas): Open pods, check if grains have nibbling or worm entry signs, remove infested grains.
Dry Lubia: 1. Boil: Boil with 3x water amount, turn off and leave covered ∼3 hours. 2. Check: Spread 10-15 grains on palm, look for dark spot under thin peel. Put other hand on top, flip and check other side. If dark spot found - peel and check for insect. Black spot on peel is natural growth, brown/orange surface spots are not infestation. If 3 definitely infested grains found - open and check all inside. If heavy infestation - do not use.
Carrot: Premium quality - considered clean.
Silka Leaves (Spinach/Beet leaves): Regular growth heavily infested, maggots inside leaf thickness that don't come off by washing. Use only special "without worms" growth under reliable hashgacha. Soak in water with little liquid soap and wash each leaf thoroughly.
Karti (Leek): Cut and remove: A. Green leaves. B. Root area (about 1 cm) at other end. C. First outer layer. Cut central white part lengthwise, separate all layers and soak in water with little soap for 2-3 minutes. Wash layer by layer under running water rubbing lightly with fingers both sides.
Red Beet: Cut into slices across, 1-1.5 cm thick, look for white worm tunnel and remove affected area. Can also slice and check after cooking.
Fish Head: Carp, Buri, Silver carp heads - use only from store under mehadrin hashgacha. Salmon head - open, remove gills, wash well and check for brown parasites 1.5-2.5 cm long (even with mehadrin hashgacha). Other fish heads - generally clean.
Honey: Considered clean.