I would like to self pollinate some plants the spring, how does one keep the stray pollen away?

Do I have to cover with muslin or simular material to stop insects or pollen from another plant

I would like to self pollinate some plants the spring, how does one keep the stray pollen away?
That is exactly what you must do. Check a nursury supplier for materials to do this.
Reply:Put a plastic bag over a group of buds(before they bloom.)That applies to the pollinator and the plant to be pollinated.This way you are sure to have at least one of each ripe at the same time.Pollinate on a windless day if at all possible using a heat sterilised fine brush.Once finished fix new plastic bags on pollinated blooms untill they are obviously drying up.Collect the seed and away to go.
Reply:I think that using a paper or cloth bag is probably a better idea than plastic - plastic will trap moisture and heat and may cause rot in the blossoms. Paper or cloth will breathe and shouldn't cause problems.
Reply:After you pollinate it, tie a baggie over the flower.
Reply:Yes. You need to isolate your plants from the environment.
Reply:Put a plastic bag over the flower you want to fertilize.