**When the total number of chips in the tournament is about 40x the big blind, the tourney is about to end.
**
That single statement drives everything. Decide how many players you have and how many to chips you’re giving to each. It doesn’t matter what you decide. Say N players and C chips. Then there are NC total chips in the game. Make up a blind schedule such that the blinds reach NC/40 at the time you want everyone to go home.
Example: 7pm to 10pm desired. 10 players, 2000 chips = 20000 chips to start. Tourney will end near or before the round with BB=NC/40=500. So, set the ending round:
7:00 BB=?
10:00 BB=500
For the beginning round, decide how you want people to drop away: quickly at first, then slowly ==> bigger starting blinds (~C/25). Slowly at first, then more quickly ==> smaller starting blinds (~C/200). Let’s say you pick C/100. Then:
7:00 BB=20
10:00 BB=500
Use the clock for rounds. Say you want blinds to increase every 30 minutes. (Doesn’t matter much.) With the first and (estimated) last rounds set, just fill in the middle!
7:00 20
7:30 40
8:00 80
8:30 100
9:00 200
9:30 400
10:00 500
(small blinds ~1/2 the BB. Doesn’t have to be exact, e.g. SB=50,BB=75 is perfectly fine.)
Adjust the middle numbers to suit your desires according to the following corollary: If the average stack size is below 20BB, the field will thin itself imminently. Notice that in the above tourney, the (constant!) total chip count is 20000. Thus, until a player gets eliminated, the average stack size goes: (1) 100BB (2) 50BB (3) 25BB. Thus, expect to be down to 9 players sometime around round (3), certainly no later than. If that’s too soon/late for you, adjust the blinds down/up for the preceding rounds, but you have to keep the 10:00 round frozen because that sets the end time (following the bolded rule at the top.)
That’s how you tune a tourney. YMMV.
One last thing: Two or three chip colors is plenty. 25/100/500 is reasonable. (The above example used units of 20, in which case you’d use 20/100/500.) For a 2000 chips tourney, you might give everyone 1x500, 3x100, 8x25. If you have enough to keep to two colors, even better until later in the tournament.
On edit: obviously the overall chip scale is arbitrary. You could take the entire above post and divide by 20. Thus, give everyone 200 chips and the blinds start at 1 unit and reach 50 units at 10:00. Whatever you’re comfortable with.