I was thinking about this a while ago, so I had this partially written.
Post 1: The Lottery
I don't like the current lottery, and I haven't heard a lot of other options that I like. I want unlucky/bad franchises to have a chance to turn themselves around, but I don't like good players languishing away on perpetually bad teams, how a team getting a high pick is still better off being bad the next year to get another high pick, and how the current system really incentivizes losing and de-incentivizes winning if you're not an immediate contender. It's basically created a bad disparity in the NBA of Lottery and Contenders and a No Man's Land middle class; I would much rather see that the middle class consists of teams on the rise or previous contenders a little over the hill rather than how it currently consists of teams that are stuck going nowhere.
In thinking about this, here is my tentative proposal:
-Entire draft order is determined by equal random chance (each team has 1 ping pong ball; draw in order of 1st to 30th pick then again for 2nd round).
-Winning the lottery means you cannot get a top 3 pick the next year, a top 2 the following year, and the top pick in the 3rd year following the lotto win. Exception: if your #1 overall pick is no longer on your roster (i.e. traded), you re-gain eligibility for winning the lotto again. Such a transaction would have to be completed before the lottery is run.
-Winning an NBA title causes the same restrictions to draft picks
-NBA runner-up and the team that earns the #2 pick are inelligible from winning the lotto for 1 year
-There is no "swapping" first rounders of the same year until after the draft order has been determined, since a swap is totally random. You can trade future firsts as under the current rules. Note: if you've acquired the future first round pick of a team that has won the championship, that pick is NOT subject to restrictions since it's YOUR pick now, so it's your logo on the ping pong ball. At least until the draft order is set.
-You COULD make "...the better of two..." type qualifications on picks though, for trade purposes. In other words, I could trade you player x and guarantee that we swap picks if mine is better if you give me player y, who is a little better than player x.
Work in progress.