symbols 4 rentry (afaik all should be open!)
shapes: ♡ ❥ ☆ ♫ ♪ ✿ 𝄞 ⏾ ⟣ ➷ ✧ ⌕ ﹆ ◯ empty spacer: ( ) dots: ･･･ ˚ ｡ 。 ˳ frills/curves: ︵ ◡◡ ◠◠ ⁐ ⏜ ⏝ 𓎡 ⌣ ︶ ⏔ ⏕ ⏖ 𓏏𓏏𓏏 𓎟𓎟 ᐢ ∪ lines: ┊┈ ═╪ ━━╋━ ═ borders: ❛❜ ❝❞ ◜◞ ◟◝ 『』₍ ₎ ⁽ ⁾ ╰ ╮⪩ ⪨ ❨❩ character spacers: ﹐﹔﹕﹑﹒ꜝ﹗﹖﹟ X'es/crosses: ⁺ 𓏴 † ♱ ﹢ small: ˵ ⋆ ⑅ ⊹ ᵎᵎ arrows: ⤵︎ ⤹ ⤷ ↺ ↻ squiggles: ∿ 𓂃 ⋎ ⊂ ribbons: 𝒢𝒞 𝜗𝜚 mini numbers: ¹ ² ³ ⁴ ⁵ ⁶ ⁷ ⁸ ⁹ ⁰ ₁ ₂ ₃ ₄ ₅ ₆ ₇ ₈ ₉ ₀ etc: ʬʬ ⚢ ⚣ ⋌
there are many more, but these are just some of the most popular/aesthetically pleasing. for more open symbols, look here!