Oracle and execution plans I have used the following procedure to view the last execution plan

create or replace procedure display_plan
as
begin
  for c in (select plan_table_output t from table(dbms_xplan.display_cursor('', '', 'allstats advanced last'))) loop
    dbms_output.put_line(c.t);
  end loop;
end;


With dbms_xplan.display_cursor it is possible to specify the SQL_ID. I understand that you can get a list of SQL_IDs from the table V$SQL but how does one decide what ones belong to the current session?
Yes, you can specify the SQL_ID.  The usage would be something like this:

SELECT * FROM table(DBMS_XPLAN.DISPLAY_CURSOR('gwp663cqh5qbf',0));


To find the SQL IDs for the current session, you'll first need to get the SID for your session, and then search v$session for the related SQL_IDs:

select sys_context('USERENV','SID') from dual;
select SQL_ID from v$session where SID='yoursid';


If the SQL aged out of the cursor cache, you may be able to find it in v$active_session_history:

select SQL_ID from v$active_session_history where SESSION_ID='yoursid';


I would recommend reading the manual page for DBMS_XPLAN to get the full details.