diff --git a/MIGRATION_PLAN.md b/MIGRATION_PLAN.md
index 62e382b..bdfc3ee 100644
--- a/MIGRATION_PLAN.md
+++ b/MIGRATION_PLAN.md
@@ -184,28 +184,46 @@ Source of truth for the step-by-step rebuild. Keep this concise and up to date.
 ## Phase 6 — UX / Editing
 
 ## Phase 6.1 — Confirm scope and priorities
-- [ ] Confirm scope and priorities for this phase
+- [x] Confirm scope and priorities for this phase
+- [x] Decision: No cursorcolumn (as per AGENTS.md)
+- [x] Decision: No auto-window toggling behavior (keep settings static)
+- [x] Decision: No motion plugin (skip leap/flash)
+- [x] Decision: Move undotree to separate Phase 6.8
+- [x] UX settings to add: signcolumn, cursorline, colorcolumn
 
-## Phase 6.2 — Comment.nvim
-- [ ] Add `numToStr/Comment.nvim`
+## Phase 6.2 — Core UX settings
+- [x] Add signcolumn=yes (always show gutter for LSP/git)
+- [x] Add cursorline (highlight current line)
+- [x] Add colorcolumn=80,120 (visual guides)
+- [x] No cursorcolumn (excluded as per AGENTS.md)
+- [x] No per-window autocommands (keep simple)
 
-## Phase 6.3 — Surround
+## Phase 6.3 — Comment.nvim
+- [x] Add `numToStr/Comment.nvim`
+- [x] Configure for gcc/gc commenting
+- [x] Add keymaps if needed
+
+## Phase 6.4 — Surround
 - [ ] Add `kylechui/nvim-surround`
+- [ ] Minimal config with default keymaps (ys, ds, cs)
 
-## Phase 6.4 — Autopairs
+## Phase 6.5 — Autopairs
 - [ ] Add `windwp/nvim-autopairs`
+- [ ] Integrate with nvim-cmp
 
-## Phase 6.5 — Indent guides
+## Phase 6.6 — Indent guides
 - [ ] Add `lukas-reineke/indent-blankline.nvim`
-
-## Phase 6.6 — Motion (leap/flash)
-- [ ] Add `ggandor/leap.nvim` or `folke/flash.nvim`
+- [ ] Configure scope highlighting
 
 ## Phase 6.7 — Folding (UFO)
 - [ ] Add `kevinhwang91/nvim-ufo` for folding
+- [ ] Configure with Treesitter and LSP providers
+- [ ] Add fold keymaps (za, zR, zM, etc.)
 
-## Phase 6.8 — Optional: Undotree
-- [ ] (Optional) Add `mbbill/undotree`
+## Phase 6.8 — Undotree
+- [ ] Add `mbbill/undotree`
+- [ ] Add keymap to toggle undotree
+- [ ] Configure minimal settings
 
 ## Phase 7 — Git, Markdown, Copilot, Formatting
 
diff --git a/README.md b/README.md
index a7e79f6..70e1cf0 100644
--- a/README.md
+++ b/README.md
@@ -35,6 +35,15 @@ Record every decision here with a short rationale. Append new entries; do not re
   - Parameter swapping: `<leader>a`/`<leader>A` to swap with next/prev parameter
   - Auto-tag for HTML/PHP/JS/React/TS/Vue files (auto-close, auto-rename, close-on-slash)
   - Indent disabled initially (experimental); can enable per-filetype if stable
+- 2025-12-07: UX/Editing Phase 6 decisions:
+  - Enable signcolumn=yes (always show for LSP diagnostics, git signs)
+  - Enable cursorline (highlight current line)
+  - Enable colorcolumn=80,120 (visual guides at 80 and 120 chars)
+  - NO cursorcolumn (as per AGENTS.md)
+  - NO auto-window toggling behavior (keep settings static, no per-window autocmds)
+  - NO motion plugin (skip leap/flash for simplicity)
+  - Undotree moved to separate phase (6.8)
+  - Comment.nvim for commenting (gcc/gc/gbc/gb keymaps)
 
 ## Project-Local Configuration (design)
 
diff --git a/lazy-lock.json b/lazy-lock.json
index eb68f21..28a14b2 100644
--- a/lazy-lock.json
+++ b/lazy-lock.json
@@ -1,4 +1,5 @@
 {
+  "Comment.nvim": { "branch": "master", "commit": "e30b7f2008e52442154b66f7c519bfd2f1e32acb" },
   "LuaSnip": { "branch": "master", "commit": "3732756842a2f7e0e76a7b0487e9692072857277" },
   "cmp-buffer": { "branch": "main", "commit": "b74fab3656eea9de20a9b8116afa3cfc4ec09657" },
   "cmp-nvim-lsp": { "branch": "main", "commit": "cbc7b02bb99fae35cb42f514762b89b5126651ef" },
diff --git a/lua/plugins/comment.lua b/lua/plugins/comment.lua
new file mode 100644
index 0000000..2177510
--- /dev/null
+++ b/lua/plugins/comment.lua
@@ -0,0 +1,24 @@
+-- Phase 6.3: Comment.nvim for commenting
+return {
+  'numToStr/Comment.nvim',
+  event = 'VeryLazy',
+  opts = {
+    -- Use default keymaps: gcc (line), gc (visual), gbc (block), gb (visual block)
+    padding = true,       -- Add space between comment and text
+    sticky = true,        -- Keep cursor position after commenting
+    ignore = '^$',        -- Ignore empty lines
+    toggler = {
+      line = 'gcc',       -- Line comment toggle
+      block = 'gbc',      -- Block comment toggle
+    },
+    opleader = {
+      line = 'gc',        -- Line comment operator
+      block = 'gb',       -- Block comment operator
+    },
+    extra = {
+      above = 'gcO',      -- Add comment on line above
+      below = 'gco',      -- Add comment on line below
+      eol = 'gcA',        -- Add comment at end of line
+    },
+  },
+}
diff --git a/lua/settings.lua b/lua/settings.lua
index 1ae05c4..8da4de0 100644
--- a/lua/settings.lua
+++ b/lua/settings.lua
@@ -30,3 +30,8 @@ vim.opt.listchars = {
 -- Enable line numbers and relative line numbers
 vim.opt.number = true
 vim.opt.relativenumber = true
+
+-- Phase 6.2: UX settings
+vim.opt.signcolumn = 'yes'        -- Always show sign column (for LSP diagnostics, git signs, etc.)
+vim.opt.cursorline = true         -- Highlight current line
+vim.opt.colorcolumn = '80,120'    -- Visual guides at 80 and 120 characters