1. pH greater than 7: This is the most fundamental characteristic. The pH scale measures the acidity or alkalinity of a solution. Values below 7 indicate acidity, values above 7 indicate alkalinity (basicity), and 7 is neutral.

2. Slipperiness or soapy feel: Basic solutions feel slippery to the touch because they react with the oils and proteins on your skin, forming a soapy film.

3. Bitter taste: Many basic solutions taste bitter, though you should never taste them directly to test this.

4. Ability to turn red litmus paper blue: This is a classic chemical test for basicity. Litmus paper is a pH indicator. Red litmus paper turns blue in the presence of a base.

5. May cause discoloration or react with certain materials: Some basic solutions can react with metals or other materials, causing discoloration or other changes.

Important Note: It's essential to remember that some basic solutions are highly corrosive and can be dangerous. Always handle them with caution and appropriate safety equipment.