Today Sensei Andrew had us doing throwing practice with a crash mat and went over three techniques:
Deep Squat Seio-Nage
Go in for a standard seio-nage but squat down as low as you can and pop the uke up into the air with your hips as you complete the throw.
Mikikomi Throws
Any regular throw but with a makikomi. We did Harai-Makikomi, Uchi-Mata-Makikomi, and Koshi-Makikomi.
Ura-Nage
We practiced this as a count to a hip throw. When the tori steps in and attacks you sink your weight and perform the throw. Two key things here were to squat down and thrust your legs into the tori so that their legs would kick out. The other was to turn around so that you're on top of the tori.
Demonstration video:
http://www.youtube.com/watch?v=6Ag8Gl76BQs
The crash mat throws I practiced were O-Goshi, O-Guruma (two variations), Koshi-Guruma, Uchi-Mata, Tai-Otoshi, Seio-Nage (3 variations) and Harai-Goshi.