Record Digging is a science to some. There are no guarantees. You do have bad digs but you can help yourself make smarter decisions so that you come away partially satisfied.First I think its important to know that you can get good vinyl for cheap. Raid those dollar bins. Lets say you have 50 dollars to spend. Its better to get 50 dollar records or 25 two dollar records. There are no guarantees anyway so getting more records increases your chances of finding the right samples. Study Record Covers. That's a science within itself. For instance you say you want trippy pyschedelic music. I'm assuming you mean Pyshhedellic Rock. Look for album covers that represent that era. That's mid 60's early 70's Rock. I love Orchestral too. Movie Soundtracks have tons of Orchestral Samples. You'll be suprised at the samples you'll find from Soundtracks. Movies you never expected. Rocky, Jaws, Midnight Express etc... Just look for the ones who say that the music was composed by Orchestras.As time goes on, you'll become familiar with certain Composers like John Williams, Enrico Morricone etc... Trippy can also mean Tri hop type stuff-That Dark electronic stuff like Tricky. I dont think you mean this.

Jazz has some of the best basslines. Other than that I'm not a big fan either. It can de depressing as hell, non melodic and its too much improvisation. Its like musicians freestyling, coming off the top of the head.