A hand lens is a necessary tool to check for the viability of the predators. Timing of the release after arrival is important. Adult crypts are hungry and thirsty and need to be released soon after delivery. I mist the greenhouse before setting them free. Feed them with wheast to encourage them to stay in the greenhouse, especially if you have a very low pest population.
Lacewings arrive as eggs and often hatch a few days later.
You want to release them as soon as they hatch. A hand lens can help you determine when hatching has finished. If you wait too long, they will eat each other. Nematodes come in an agar base that needs to be dissolved in water. You should be able to see them swimming around with a hand lens.