Staying on Lane or Pulling

Is the lane pushed / your creeps fighting opponent creeps near opponent tower?

Yes

No

2v2 Laning

Are the opponents pushing/auto-attacking like mad?

Yes

No Pulling
(24/7 babysitting)

Otherwise, tower will be damaged or your carry will die if he made a mistake.

No

Is your carry free farming ?

Yes

Your choices

Go Pull -
Only pull after you stacked or
do a chain pull

More harassment / more deny

Rune control / Go gank

Your Special Taktic

No

Survival /
Make plays /
Kill them when they make mistake /
Call gank /
Switch lane

2v1 Laning

Is the solo opponent getting any farm/gold?

Yes

Very aggresive harassment
to chase the opponent out of the exp range

Solo opponent's level should equal or lower than your level (regardless you are pulling or harassing mad) and your carry should have complete free farm.
Notably againt heroes like DS, you will need to do very aggresive harassment from level1.

Go Pull

No

Your choices

Go Pull -
Only pull after you stacked or
do a chain pull
Under the condition that your carry has complete free farm.

Solo opponent will get some exp/gold eventhough you have denied waves of your allied creeps.

Constant Harassment

Make the solo opponent hates you.
By doing this however you may force the opponent to gank mid.

Rune control / Go gank /
Special Tactic