Toiltery bags are many steps above your regular ziploc bags.
Good toilet bags are lightweight and leak resistant. They come with flexible internal organization (compartments etc), and are easy to hang.
Keep in mind that toiletry bags are not technically compliant with the TSA’s 3-1-1 liquids rule as they’re not fully transparent, but people still use them.
The best toiletry bag: Eagle Creek Pack-It Specter Wallaby Small (large hook for easy anywhere hanging, easy to pack)
The second best toiletry bag: Sea to Summit Travelling Light Hanging Toiletry Bag 9same features as Eagle Creek model, but smaller)
The best toiletry bag for more stuff and longer: L.L.Bean Personal Organizer Toiletry Bag (6.4 L capacity, 12+ compartments)
The best affordable toiletry bag: Eagle Creek Pack-It Specter Quick Trip (multiple pockets for better organization, 1 ounce weight)