put a brown paper bag tied over the flower and leave for as long as u can ,then cut bag off with seed inside and store in a drydark cool place till spring. been careful of mice etc

Make sure the seeds are properly dried or you may get mould growing on them. I use the plastic tubes in which Steradent tabelts are sold.

I use small brown envelops but as previously said make sure the seed is ripe and dry.

Use paper bags or envelopes instead of plastic bags or containers. From previous experience I have found that airtight containers can sometimes cause the seeds to rot as it's almost impossible to dry them completely. Paper will allow air circulation and help them dry out more.

I store mine in a cool dry place like a shed and try not to keep them longer than a year as a lot of seeds will lose their viability to germinate. What type of seeds are you trying to harvest?

I collect a lot of seeds, intially into a small creme freche pot until dry and then into paper packets or glassine packets. Many go to a seedex but the ones that I keep are stored in a fridge.