Data Cleaning Formula Suite

I need help cleaning messy data in Excel. Here are my data issues:

**Data Problems to Fix:**
- [ ] Extra spaces (leading, trailing, double spaces)
- [ ] Inconsistent capitalization
- [ ] Mixed data types in one column
- [ ] Text in number columns
- [ ] Date format inconsistencies
- [ ] Special characters to remove
- [ ] Duplicate entries
- [ ] Merged cells to split
- [ ] Columns to split or combine
- [ ] Other: [describe]

**Sample of Messy Data:**
[Paste 5-10 rows of your actual messy data]

**Desired Clean Output:**
[Describe or show what the clean data should look like]

**Environment:**
- Excel version: [365, 2019, 2016, etc. or Google Sheets]
- Number of rows to clean: [approximate]
- One-time cleaning or recurring: [one-time / need repeatable process]

Please provide:
1. Formulas for each cleaning task
2. Step-by-step cleaning workflow
3. Power Query approach if applicable
4. Validation formulas to check results
5. Tips for preventing dirty data in the future