Germinating tiny seed inside a bag (or not)

Emerion

My heart sinks every time the instructions on a seed packet say to place the pot or tray in a polythene bag, because I am a World-class killer of seeds in a bag: I have never germinated a single seedling in about 20 years of trying. I either get soggy and mouldy compost, or bone dry, and usually both, whilst failing to regulate the conditions. I have tried growing mediums  with varying drainage qualities from mostly sand through to standard potting compost and everything in between. Also bags with holes in, the corner cut off, or no holes.  I’ve tried with and without heat, as instructed on the packet. Is there another way to grow tiny flower seeds that will give me a fighting chance? The choice of seeds is so much wider than that available as plants, and I love germinating seeds. 

Purplerain

Some people suggest mixing tiny seeds with fine sand and then sprinking them lightly on top of the compost. Some need a light covering of sieved compost others not, depending on what they are. Sit the seed tray in water to pull the seeds down and remove when it feels damp but not wet. I have never used a bag to germinate seeds so don't know if it works.