pointed red and black snelm
round red and black snelm
pointed blue snelm - note for all snelms: I don't think these appear for hard clue scrolls, so if you only complete hard clue scrolls, don't bother.
Splitbark helmet -
do keep it ; this item is unused outside of treasure trails and a pain to obtain. Hard clue scrolls only.
Mud pie - annoying item to obtain, keep it. Be sure to turn auto-retaliate OFF, else you'll waste it against the infamous Double Agent.
Iron pickaxe
Steel pickaxe
Bronze hatchet - you can even get a free one from Bob in Lumbridge

Iron hatchet
Rune hatchet - I guess everyone has this in their bank already. Hard clue scrolls only.

Elemental Shield: might want to keep this one
Unenchanted Tiara - easy to obtain
Air Tiara
Blue flowers - I never needed this item myself, but I believe it is from an Easy clue scroll.
Yellow flowers - I never needed this item myself, but I believe it is from an Easy clue scroll.
Wood Camo Top - unusual item, keep if doing lower-level clue scrolls.
Polar Camo Top - unusual item, keep if doing lower-level clue scrolls.
Polar Camo Legs - unusual item, keep if doing lower-level clue scrolls.
Unblessed Silver Sickle - easy to make plus the Grand Exchange should have a few too.
Staff of Air
Fire Battlestaff - required for hard clue scrolls, and since it is kind of ''expensive'' I'd keep it. If not, you can always high alch it afterwards to get your money back.
Unholy symbol
Holy symbol