"Success is the sum of small efforts repeated"
What you need to know
Trim mainsail leach with vang for run
Set up for beat and adjust main twist with backstay and mast ram only
If you are sailing on a pond, conditions will be quite variable. As a rule I set my boat up for the lightest conditions but make sure I can oversheet the main to control the leach and create power in the gusts
Run through checklist for boat setup
Check radio setting are all correct as per checklist
Check rudder movement
Scan whole boat to make sure all is OK
Check bung inserted and secure
Is burgee fitted
If you review several of the videos and articles on tuning an IOM (HERE), there is a consistent process people have adopted which seems to work.
Having set up your boat with the mast rake according to the boat plan, enough shroud tension to stop the leeward shroud from hanging loose when beating to windward, enough backstay to straighten the mast and 15-20 mm of chord depth in the foot of the main You are then ready to start.
Set the boat up on a run with the main boom just touching the shrouds and hold it in wind that you expect on the course. Tighten the kicking strap until the leach twists by an inch or so. Do this on both port and starboard to make sure the mast is centred and straight. Look to see if you have more twist on one side or the other.
Set up the mainsail
Set up for close hauled and adjust mainsail twist with the backstay and mast ram. The goal is to have the top batten parallel to the centreline of the boat and a fair luff shape consistent top to bottom when viewed from behind and leeward. If you are having problems with the mainsail leach tension between the run and beat, check that you have some packing under the bottom of the gooseneck. 2 layer of deck patch should do it. This alters the geometry so the kicker tightens as the boom goes out from a beat to a run.
Check the mast bend looking down from the top of the mast. On an A rig there should be a slight S curve with slight reverse bend at the mast ram. The B rig should have a fair curve as will the C rig but to a lesser extent. If you followed the instructions in Boat Tuning and Setup and noted the settings, there should be very little to do other than adjust for more wind or less wind.
If you are sailing on a pond surrounded by trees, conditions will likely be quite variable. As a rule I set my boat up for the lightest conditions but make sure I can oversheet the main to control the mainsail leach and hold it firm in puffs to create power and acceleration.
Adjust the jib
Once you are happy with the main, look at the jib. The sheet setting you will have pre defined but you need to check the leach. Looking at the boat from behind and to leeward see that the leech twist is parallel to the mainsail. Adjust the topping lift to make it so.
Run through checklist for all your settings to ensure nothing is out of place.
Check the radio settings are all correct as per checklist. You may need to micro adjust the sheet setting for the conditions. As a rule, look for close sheeting with the main boom centred on flat water and ease the booms out slightly as the wind and waves increase.
Check rudder movement is OK and finally scan the whole boat to make sure all is OK and add the burgee to the top of the mast.
Check bung is inserted and secure and you are ready to launch.