I tried making a sliver deck once or twice so I could finally use my Sliver Queen that I pulled from a Stronghold booster waaaaaay back in the day, but could never get it to work properly. I didn't feel like buying a bunch of singles for an unproven deck either. I almost invariably stick to two colors, but I sometimes think about building a Necra deck since I think the W/G/B color combo is an interesting one.
I just buy singles every so often when I want to update my decks (though I have been out of the game for a while, so I haven't recently). I have found that buying singles tends to be more economical than grinding through boosters. I guess one advantage of playing Vintage like I do is that you don't have to update terribly often. I think the average age of the cards in my suicide black deck is around 10 years or so, and it is mean enough that modern replacements are very rare. You'll never see another Necropotence again!
Yeah. I totally agree. Two is the most I used myself. Which was kind of what killed my Kavu. Red and Green Kavu were good staples, but so many tactics, even simple, needed 3 or so to be particularly well oiled. lol My vampire deck circa... er... Whatever came after Apocalypse... was pretty fun, but kind of messy in a 'let's use this maybe twice out of five games' kind of way. I rocked the Baron just because he looked cool. lol
But yeah, hand selecting is how I worked on my Vampires, Merfolk, and sooooort of just to have generic and only moderately themed decks. (Like Ihsan's Shade who I rolled with for a time, also 'because he is cool'. Boosters are fun to open, but I feel like the glory days of booster packs is well in the past. At least for me.
In fairness I have gotten about two free pre-made decks as gifts, and one of those rat ninja decks from Kamigawa just because it was cheap at the time. lol