I find that I always use a guided mediation. I lose focus too quickly if i don't, my mind just wonders off thinking about what i have to do and it can get quite stressful. Meditating with a guided mediation helps me relax and focus my thoughts.
Zen type music or soft sounds most often accompany my meditation. However, I like to also meditate to Apps such as Breethe, Aura, and Ten Percent Happier as long as there aren’t long pauses as I enjoy learning or brushing up on skill offered in the Apps. Sometimes, when my spirit is already calm and quiet and the environment I am in supports it, I will sit in Lotus and place my hands in an Eastern Indian Position learned through Stanford, and focus on complete silence, breath, and body. That is my highest form of meditation. That is when Contemplative Prayer feels perfectly loving, open and receiving. And still, when I am in grief or hurting, I find yogic meditation to be most beneficial. Then I will often use an App like Yoga Studio or Breethe. I am blessed though. I have done meditation for decades and can usually relax into it. I do not see it as a chore but a blessing and enter it with gratitude and enjoyment.
My needs change based on the day so I switch it up. Sometimes I do guided meditation, just music or silence. Many find silence difficult. When you find yourself meditating in silence with a distraction (like when your mind is annoyed by a ticking clock) make the distraction your point of focus (listen for the next tick).