I bring just about everything I normally use, I just put things in travel-sized bottles when possible. Otherwise just pack full size in my checked luggage.
When appropriate, I like to unscrew the top, tightly stretch some saran wrap over the opening, then put the cap back on, then put some saran wrap around the whole thing. If I'm bringing fragrance bottles I'll wrap them in saran as well. It holds lids on tightly while simultaneously providing a shield so if some does leak it doesn't get all over the place.
When appropriate, I like to unscrew the top, tightly stretch some saran wrap over the opening, then put the cap back on, then put some saran wrap around the whole thing. If I'm bringing fragrance bottles I'll wrap them in saran as well. It holds lids on tightly while simultaneously providing a shield so if some does leak it doesn't get all over the place.