Do Different Meditations Support One Another? I have tried meditating on compassion, just as I've tried meditating on the breath. Currently, these days, I find it hard to meditate on compassion.

My question is: Would practising meditation of any kind improve a meditation of another kind, e.g. practising breath meditation would increase compassion meditation's effectiveness? 

Simply put, does every meditation type share at least some aspects with others, some basic features such as--I suppose--gathering attention, learning patience, and so on? Thus, improving those aspects through breath meditation might extend to compassion meditation?

Thank you
Yes they do support eachother imho. Whenever one directs the mind to a wholesome theme, to rouse gladness or energy, when keeping the mind on the theme one is not oblivious to the theme and this concentration is a good skill to develop. Furthermore the foremost quality for the attainment and awakening to the truth is effort and it requires contemplation and coming to agreement.

Therefore it is evident that when mind is somehow impaired one should direct the mind to a skillful theme for a purpose of gladdening or composing otherwise. When mind is unconstricted and pliant one can then retreat from that wholesome theme and stop thinking about it and just be mindful and at ease.

Traditionally speaking the guardian meditations are largely accepted to be necessary among insight and samatha meditators alike afaik. I advocate contemplation in general; https://docs.google.com/document/d/1kZxstsAvjhj9Svc47RUKRIyKQMuHMD4adIvr_7pp2uI/edit?usp=drivesdk


  “There is the case of a monk who remains focused on the body in &amp; of itself—ardent, alert, &amp; mindful—subduing greed &amp; distress with reference to the world. As he remains thus focused on the body in &amp; of itself, a fever based on the body arises within his body, or there is sluggishness in his awareness, or his mind becomes scattered externally. He should then direct his mind to any inspiring theme. As his mind is directed to any inspiring theme, delight arises within him. In one who feels delight, rapture arises. 
  
  In one whose mind is enraptured, the body grows calm. His body calm, he feels pleasure. As he feels pleasure, his mind grows concentrated. 
  
  He reflects, ‘I have attained the aim to which my mind was directed. Let me withdraw [my mind from the inspiring theme].’ He withdraws &amp; engages neither in directed thought nor in evaluation. He
  discerns, ‘I am not thinking or evaluating. I am inwardly mindful &amp; at ease.’
  
  “This, Ananda, is development based on directing. 
  
  And what is development based on not directing? A monk, when not directing his mind to external things, discerns, ‘My mind is not directed to external
  things. It is unconstricted [asankhitta] front &amp; back—released &amp; undirected. And then, I remain focused on the body in &amp; of itself. I am ardent, alert, mindful, &amp; at ease.’
  
  “When not directing his mind to external things, he discerns, ‘My mind is not directed to external things. It is unconstricted front &amp; back—released &amp; undirected. And then, I remain focused on feelings… mind… mental qualities in &amp; of themselves. I am ardent, alert, mindful, &amp; at ease.’ 
  
  “This, Ananda, is development based on not directing.