Why the "right" style depends on the actual problem, not popularity
Mindfulness meditation is the most commonly recommended starting point mostly because it has the largest research base and the lowest barrier to entry, not because it objectively outperforms every other style for every goal -- someone specifically working through anger or resentment, for instance, may get more out of loving-kindness practice than out of mindfulness alone, even though mindfulness is more frequently recommended by default.
Consistency matters more than which style you pick
Across meditation research generally, the strongest predictor of benefit is regular practice over time rather than which specific style is used -- a short daily practice in a style that is actually sustainable tends to outperform a longer or more "advanced" practice that gets abandoned after a few weeks.
Frequently Asked Questions
Do I need to sit cross-legged on the floor to meditate properly?
No -- sitting in a chair, lying down (except when drowsiness is a concern), or even walking are all legitimate postures depending on the style. What matters more is a stable, comfortable position that will not itself become a distraction.
How long should a beginner meditate for?
Starting with 5-10 minutes a day and building consistency is generally recommended over starting with a long session that is hard to sustain -- a short practice done daily tends to build the habit and the skill faster than an occasional long one.