Presenting is a skill, and an expression of your emotions, so, find something that your man will really love being presented. As you make more projects you'll have more bits of leftover wax. How do you remember what sort of wax you used? If you've got a lot of projects you may wish to think about employing some masking tape to keep record right there on the wax.
Colour and perfume might be more easy to notice straight from the leftover wax but noting this on the tape would be a smart idea too. If you have bleached leftover wax adding it all together sounds right. If you have coloured wax you might want to plan out how you wish to layer the colours into your new candle or if you're going to mix 2 colours together and see what occurs. No matter what you choose the method for liquefying the leftover wax will be the same. There's nothing better for ladies than an opportunity to cosset themselves, let her revive with a spa treatment certificate presented by you, or better yet take her on a mini holiday to a spa resort.