I am skipping all filler episodes and arcs in my viewing but not the Cover Stories episodes or arcs.

Those filler episodes are episodes:
54-61
131-143
196-206
220-228
291-292
279
303
326-336
382-384
406-407
426-429
575-578
626-628
747-750
Special 4

Those filler arcs are:
~Sea of Survival: Super Rookies Saga (1st Half of One Piece)~
Warship Island Arc (East Blue Saga): Episodes 54-61.
Post-Alabasta Arc (Alabasta Saga): Episodes 131-135.
Goat Island Arc (Sky Island Saga): Episodes 136-138.
Ruluka Island Arc (Sky Island Saga): Episodes 139-143.
G-8 Arc (Sky Island Saga): Episodes 196-206.
Ocean's Dream Arc (Water 7 Saga): Episodes 220-224.
Foxy's Dream Arc (Water 7 Saga): Episodes 225-228.
Boss Luffy's Historical Special (Water 7 Saga): Episodes Special 4, Episodes 291-292, 303 and 406-407.
Lovely Land Arc (Thriller Bark Saga): Episodes 326-335.
Chopper Man Special (Thriller Bark Saga): Episodes 279 and 336.
Spa Island Arc (Thriller Bark Saga): Episodes 382-384.
Little East Blue Arc (Summit War Saga): Episodes 426-429.

~The Final Sea: The New World Saga~ (2nd Half of One Piece)~
Z's Ambition Arc (Dressrosa Saga): Episodes 575-578.
Caesar's Retrevial Arc (Dressrosa Saga): Episodes 626-628.
Silver Mine Arc (Yonko Saga): Episodes 747-750.

I loved the oddball nature of this show, but the way stuff is so poorly explained made me not enjoy this show very much.

If things were explained better and more frequently, the show paced itself more (it really could have used another episode or two, and the character development made more sense, I could very easily see myself enjoying this show a lot.

As it stands, that is kind of hard to do for this show.