You can also use superglue, or elastic bands, to hold plants to rocks and wood. Java fern is another easy one, like anubias.
Cryptocorynes are also easy and grow in the substrate. You might need to weigh them down with some pebbles around the roots while they root in.
Are you making sure the 'crown' of the plants (that's the bit where the leaves and roots meet) is above the substrate? Lots of plants will die off if they're buried too deeply.
Also, many plants nowadays aren't grown totally underwater and it can take a few weeks for them to adjust, so you do need to give them a chance and not think they've died!