I build my basic progs usually somehow like this:
(blah blah blah code)

Now I see how it works! We just need to optimally substitute it into the program somehow. You can see how the program works, right?

This is a less-than-a-kilobyte clone of Lights Out.
CONTROLS
First, you will go to the main menu. Press up and down to go between menu options, and Enter to select. Press left and right to switch between modes.
In-game, press the arrow keys to move along the Lights Out grid, and Enter to turn that and all adjacent lights off. You keep going until the lights are all turned off, or you can press CLEAR at any time to quit. Either way, you will be sent back to the main menu.
MODES
The first mode is Normal mode, where all the lights are turned on.
The second mode is Random mode, where it selects a random configuration of lights.
The third mode is custom. It brings you to a screen with the grid you can customize. The controls are the same as in-game, except no special rules for switching lights apply. CLEAR goes to the game with the pattern.
CODELbl S
ClrHome
"----
Ans+Ans+Ans+Ans
Disp "    SHUTDOWN",Ans," PLAY",Ans," MODE:",Ans," EXIT
3→X
1→Y
Repeat K=105
Output(5,8,sub("NORMALRANDOMCUSTOM",6Y-5,6
Output(X,1,">
getKey→K
If Ans
Then
Output(X,1,"
X+2(Ans=34 and X≠7)-2(Ans=25 and X≠3→X
Y+(K=26)-(K=24
Ans-3(Ans=4)+3not(Ans→Y
End
End
36→dim(L₁
If X=7
Goto E
If Y=3
Then
ClrHome
DelVar A1→B
Disp "
For X,1,6
Disp " OOOOOO
End
Fill(0,L₁
Repeat K=45 and sum(L₁
Output(A+2,B+1,"
rand(8
Output(A+2,B+1,sub("O*",1+L₁(6A+B),1
getKey→K
A+(Ans=34 and A≠5)-(Ans=25 and A→A
B+(K=26 and B≠6)-(K=24 and B≠1→B
6A+Ans
If K=105
not(L₁(Ans→L₁(Ans
End
End
If Y=2
Then
Repeat sum(Ans
int(2rand(36→L₁
End
End
If Y=1
Fill(1,L₁
ClrHome
"         
Output(1,10,"! SHUT "+Ans+"! DOWN "+Ans+"+------"+Ans+"!MODE: "+Ans+"!      "+Ans+"+------"+Ans+"LIGHT:"+Ans+"!
Output(5,11,sub("NORMALRANDOMCUSTOM",6Y-5,6
For(X,0,5
For(Y,1,6
Output(2+X,1+Y,sub("O*",1+L₁(6X+Y),1
End
End
DelVar X1→Y
Repeat K=45 or not(sum(L₁
Output(8,12,"
Output(8,11,sum(L₁
Output(X+2,Y+1,"
rand(8
Output(X+2,Y+1,sub"O*",1+L₁(6X+Y),1
getKey→K
X-(Ans=25 and X)+(Ans=34 and X≠5→X
Y-(K=24 and Y≠1)+(K=26 and Y≠6→Y
If K=105
Then
For(A,1,5
6X+Y
{(Ans-6)not(not(X)),(Ans-1)(Y≠1),Ans,(Ans+1)(Y≠6),(Ans+6)(X≠5
Ans(A
If Ans
not(L₁(Ans→L₁(Ans
End
For(A,X-not(not(X)),X+(X≠5
For(B,Y-(Y≠1),Y+(Y≠6
Output(A+2,B+1,sub("O*",1+L₁(6A+B),1
End
End
End
End
If K=45
Goto S
Output(8,11,0
Pause "YOU WIN!
Goto S
Lbl E
DelVar L₁DelVar ADelVar BDelVar KDelVar XDelVar YClrHome

You need to save bytes on structure of the program. Check if there are smarter ways to get to the same result. That is what's optimization is all about.

That's part of the reason I posted it here. I can't think of any improvements.

This is my code for a Cookie Clicker game with support for a TI-83+ OS 1.19 (and possibly other platforms).

DelVar L₁ClrHome
SetUpEditor CLICK
10→dim(∟CLICK
∟CLICK→L₁
9→dim(L₁
Output(3,5,"=----------- OO !CURSOR     OO*O!PRICE:     O*OO!           O*OO!OWNED:      OO !
∟CLICK(10→C
"CURSOR     GRANDMA    FARM       FACTORY    MINE       SHIPMENT   PORTAL     TIMEMACHINEANTIMATTER →Str1
DelVar S1→B
{15,E2,500,3E3,E4,4E4,1666666,123456789,4E9-1→L₂
For(X,1,9
int(L₂(X)1.15^L₁(X→L₄(X
End
{.1,.5,4,10,40,E2,6666,98765,E6-1→L₃
Output(6,6,L₄(1
Output(8,6,L₁(1
Repeat K=45
getKey→K
If K=105
Then
Output(1,1,"                "
C+1→C
Output(1,1,int(C
End
B+(K=26)-(K=24
Ans-9(Ans=10)+9not(Ans→B
Output(4,6,sub(Str1,11B-10,11
If sum(K={24,26
Then
Output(6,6,"           "
Output(6,6,L₄(B
Output(8,6,"           "
Output(8,6,L₁(B
End
L₁(B)-(K=85 and L₁(B))+(K=95 and C≥L₄(B→L₁(B
If K=95 and C≥L₄(B
Then
int(L₂(B)1.15^L₁(B→L₄(B
Output(6,6,"           "
Output(6,6,L₄(B
Output(8,6,"           "
Output(8,6,L₁(B
Output(1,1,"                "
Output(1,1,int(C
End
If K=85
Then
int(L₂(B)1.15^L₁(B→L₄(B
Output(6,6,"           "
Output(6,6,L₄(B
Output(8,6,"           "
Output(8,6,L₁(B
End
If not(S
Then
C+sum(L₁L₃→C
Output(1,1,int(Ans
End
Output(2,1,"                "
Output(2,1,int(sum(L₁L₃
S+1-4(S=3→S
End
C→L₁(10
L₁→∟CLICK
ClrHome
What do you think?