suitable, right, fitting, proper
冝 centers on the idea of something being appropriate or correct: suitable, right, fitting, or proper for a given situation.
冝 is a variant form of 宜. The character likely combines 冖 (cover) with 且 (a shelf or altar) to suggest something properly placed or arranged, but the exact historical development is uncertain.
The top 冖 is like a lid covering a shelf 且. Picture placing an item on the shelf and covering it neatly—everything is in its proper place, fitting and suitable.
For ギ, imagine a gift that is perfectly suitable for the occasion: gift -> ギ, and the gift fits just right under the lid on the shelf.