How often a validator receives block proposals, and is selected to be part of a sync committee, is entirely random. As long as you do not see missed proposals, there is absolutely nothing you can do to increase the frequency.
True randomness can feel quite odd. A validator not getting a proposal for 9 months is perfectly normal. A validator getting two proposals in a week is entirely normal. Over a large enough set, this evens out, but for a handful of validators, randomness can indeed feel unsettling.
To see the latest's statistics on block proposal frequency take a look at Lucky Staker ↗.
The tool ethdo ↗ by attestant.io ↗ can be used to query the current average frequency of proposals and sync committees.
As of early 2024, it is roughly one proposal every 4 months and sync committee participation every 5 years.
No, it's random. There is nothing you can do to increase your chances at proposals, short of running more validators.