The 'older' your coins the more 'weight' ( network weight ) they have. Everytime you move them around they start off with no weight at all and they gain weight. Basically you have to leave them be and eventually they will 'stake' and you get a block... after 110 blocks they will start staking again, starting over with zero weight...

So, just be patient... I am staking with about 1500 BTCU and I am getting a block every 750 plus blocks or so... not great but it is something... if you are staking less coins it will be a longer interval for you....

Think of the number of coins being similar to have more Gigahertz as a miner... more coins, more of the share... although you can get lucky as well and stake with just a handful of coins on occasion...